The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 02-08-2021, 07:14 PM   #1
old51sedan
Senior Member
 
old51sedan's Avatar
 
Join Date: Oct 2015
Location: Williamston, Mi
Posts: 869
Holley Carb adapter

Recently bought a offenhauser 4 barrel intake for my 292 with adapter. Just bought a rebuilt Holley 550 4 barrel carb. Low and behold it sits on the manifold sideways. I would like it to sit like a V8 with the linkage on the drivers side. I've been looking at adapters to correct this, I'm thinking they must make one, but no luck so far. Has anyone else had this situation, if so what did you do to correct it?
old51sedan is offline   Reply With Quote
Old 02-08-2021, 07:26 PM   #2
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,494
Re: Holley Carb adapter

As far as I know they don’t make one.
I saw an adaptor on a thread somewhere that was made from 1/4 inch flat plate. Holes drilled to bolt the Holley on and counter sunk holes to adapt the plate to the intake.
geezer#99 is online now   Reply With Quote
Old 02-08-2021, 07:30 PM   #3
70STOVEBOLT
Senior Member
 
70STOVEBOLT's Avatar
 
Join Date: Jun 2005
Location: Winona Lake, IN
Posts: 6,195
Re: Holley Carb adapter

Do you need an adapter to mount the carb or a linkage adapter?
__________________
70 C/10 SWB 402/TH400/3.73 "The Needy Beast"
200,000 Mile Club
Disc Brake Club

Owner installed options:
Front Sway Bar
Power Steering
Power Brakes
Cigar Lighter
Courtesy Lights
Deluxe Side Markers
Wiper Delay
Power windows
Power Locks

Coming soon: EFI

2015 Silverado 1500 LS 4.3/6L80/3.23
70STOVEBOLT is offline   Reply With Quote
Old 02-08-2021, 08:44 PM   #4
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 6,980
Re: Holley Carb adapter

So you want the primaries to open up and feed cylinders 1-2-3, and then the secondaries feed 4-5-6?
I prefer the carb to face the drivers side fender...
I ran a Holley 4160 [R8007] 390 CFM for 25 years on that Offenhauser intake. I had to saw off the ford-style automatic transmission kickdown lever, but since it's a Chevy and I run a manual that didn't matter. When I rebuilt in 2005, I went to an Edelbrock [500 CFM], as my 390 Holley was shot.
Attached Images
 
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.

Last edited by '68OrangeSunshine; 02-08-2021 at 08:50 PM.
'68OrangeSunshine is offline   Reply With Quote
Old 02-08-2021, 08:53 PM   #5
68Gold/white
Registered User
 
Join Date: Sep 2011
Location: Ark City, Kansas
Posts: 3,265
Re: Holley Carb adapter

Theres a company called, Transdapt that might get you there, if they are still in business.
68Gold/white is online now   Reply With Quote
Old 02-08-2021, 09:04 PM   #6
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 6,980
Re: Holley Carb adapter

I suggest modifying the '68 accelerator push rod set up to '72 style cable throttle. I ran the old push/pull rod for a long time but it was cr@ppy. Linkages came loose, small bits fell off, it even iced up once in the mountains. Too much of a Rube Goldberg. I changed to a cable and it was never smoother. And you can mount your carb in any orientation you want.
This is the cable I used. A GM cable/gas pedal assembly off a '71/'72 truck was used in the cab.
I used a Jeg's throttle return spring to retract the spring on the engine side. [A big screendoor spring to the brake master cylinder was ruled out as too Retro-Jethro].
Attached Images
  
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.

Last edited by '68OrangeSunshine; 02-08-2021 at 09:15 PM.
'68OrangeSunshine is offline   Reply With Quote
Old 02-09-2021, 10:19 AM   #7
old51sedan
Senior Member
 
old51sedan's Avatar
 
Join Date: Oct 2015
Location: Williamston, Mi
Posts: 869
Re: Holley Carb adapter

Quote:
Originally Posted by '68OrangeSunshine View Post
I suggest modifying the '68 accelerator push rod set up to '72 style cable throttle. I ran the old push/pull rod for a long time but it was cr@ppy. Linkages came loose, small bits fell off, it even iced up once in the mountains. Too much of a Rube Goldberg. I changed to a cable and it was never smoother. And you can mount your carb in any orientation you want.
This is the cable I used. A GM cable/gas pedal assembly off a '71/'72 truck was used in the cab.
I used a Jeg's throttle return spring to retract the spring on the engine side. [A big screendoor spring to the brake master cylinder was ruled out as too Retro-Jethro].
I'm looking for an adapter so that the carb will face the front of the truck. Are the offenhauser manifolds set up so that all brands of carbs have to fit sideways? I was thinking that I would be better off running a cable instead of the old linkage, I appreciate the picture of the cable. Do I have to buy a different manifold brand if They don't make an adapter or have a new adapter made?
old51sedan is offline   Reply With Quote
Old 02-09-2021, 11:06 AM   #8
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,494
Re: Holley Carb adapter

The offy intake turns them all sideways.
You’ll need to make an adaptor to change that.
Clifford intake is set up to do what you want.
geezer#99 is online now   Reply With Quote
Old 02-09-2021, 11:14 AM   #9
old51sedan
Senior Member
 
old51sedan's Avatar
 
Join Date: Oct 2015
Location: Williamston, Mi
Posts: 869
Re: Holley Carb adapter

Quote:
Originally Posted by geezer#99 View Post
The offy intake turns them all sideways.
You’ll need to make an adaptor to change that.
Clifford intake is set up to do what you want.
Dang it, I appreciate you answer, but don't like it. HAHAHA I just bought this intake, I would have bought the Clifford, but they were out of stock and I was told that they don't work well with my cast iron headers. It seems like someone would make a adapter for this, I can't be the only one with this situation....
old51sedan is offline   Reply With Quote
Old 02-09-2021, 11:40 AM   #10
Willys_MB
Registered User
 
Willys_MB's Avatar
 
Join Date: Apr 2017
Location: Boise, ID
Posts: 856
Re: Holley Carb adapter

Quote:
Originally Posted by '68OrangeSunshine View Post
I suggest modifying the '68 accelerator push rod set up to '72 style cable throttle. I ran the old push/pull rod for a long time but it was cr@ppy. Linkages came loose, small bits fell off, it even iced up once in the mountains. Too much of a Rube Goldberg. I changed to a cable and it was never smoother. And you can mount your carb in any orientation you want.
This is the cable I used. A GM cable/gas pedal assembly off a '71/'72 truck was used in the cab.
I used a Jeg's throttle return spring to retract the spring on the engine side. [A big screendoor spring to the brake master cylinder was ruled out as too Retro-Jethro].
I second the pedal upgrade. I just did this on my 68 and I wish I had done this YEARS ago. No more crappy linkage and I routed my throttle cable the way I wanted it routed. The only thing I'd suggest is spend the money on a quality custom cable, either from a shop, or one of the DIY kits. I had a HELL of a time finding one that fit. You'll be so happy you did it and you'll never look back at the old linkage
__________________
1968 GMC C2500 Long Bed Fleetside
Willys_MB is offline   Reply With Quote
Old 02-09-2021, 12:47 PM   #11
jfnar
Registered User
 
Join Date: Jul 2009
Location: Jonesboro, AR
Posts: 410
Re: Holley Carb adapter

Here's a bell crank arrangement I made for mine. I believe the aluminum elbow came with the exhaust manifold but I had to modify it. This works ok but it took a lot of trial and error and I plan to change to a cable setup when I have time.
Attached Images
 
jfnar is offline   Reply With Quote
Old 02-09-2021, 04:23 PM   #12
Palf70Step
State of Confusion!

 
Palf70Step's Avatar
 
Join Date: Jul 2002
Location: Gulfport, MS USA
Posts: 46,575
Re: Holley Carb adapter

Quote:
Originally Posted by old51sedan View Post
Recently bought a offenhauser 4 barrel intake for my 292 with adapter. Just bought a rebuilt Holley 550 4 barrel carb. Low and behold it sits on the manifold sideways. I would like it to sit like a V8 with the linkage on the drivers side. I've been looking at adapters to correct this, I'm thinking they must make one, but no luck so far. Has anyone else had this situation, if so what did you do to correct it?

http://t6performance.com/

This guy (Larry P.....) makes a new plate or modifies your original Offy plate so that it can rotate the carb 90 degrees. I have heard nothing but good from him on the 6 banger boards and I talked to him a good hour when I was planning on twisting mine around. I have not done it yet because on on install in an 81 truck, the factory cable comes in that way for the stock integrated 2bbl setup.
Attached Images
  
__________________
Bill
1970 Chevy Custom/10 LWB Fleetside
2010 Toyota Tacoma PreRunner SR5 Double Cab - DD

Member of Louisiana Classic Truck Club (LCTC)

Bill's Gallery
Life isn't tied with a bow, but it's still a gift.
Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

Last edited by Palf70Step; 02-09-2021 at 04:29 PM.
Palf70Step is offline   Reply With Quote
Old 02-09-2021, 05:46 PM   #13
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 6,980
Re: Holley Carb adapter

I've met Larry Page. Really nice guy. He used to be Pres of the Daytona chapter of Inliners International. He helped me [via emails] on tech questions when I was rebuilding my present 292 from 2002 -2005. The Man knows a lot about the Chevy L6 engine.
Larry also participates in this website as ''Twisted6'', usually on the 60-66 forum.
Still wondering if there's any advantage from having the primaries opening over 1-2-3 and secondaries over 4-5-6 with a carb-to-front orientation?
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.
'68OrangeSunshine is offline   Reply With Quote
Old 02-09-2021, 06:33 PM   #14
Palf70Step
State of Confusion!

 
Palf70Step's Avatar
 
Join Date: Jul 2002
Location: Gulfport, MS USA
Posts: 46,575
Re: Holley Carb adapter

From a few folks I talked to, unless your racing you probably won't notice much difference. I think Larry is working on a full EFI setup now for the 250/292.
__________________
Bill
1970 Chevy Custom/10 LWB Fleetside
2010 Toyota Tacoma PreRunner SR5 Double Cab - DD

Member of Louisiana Classic Truck Club (LCTC)

Bill's Gallery
Life isn't tied with a bow, but it's still a gift.
Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!
Palf70Step is offline   Reply With Quote
Old 02-09-2021, 08:18 PM   #15
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,494
Re: Holley Carb adapter

Quote:
Originally Posted by '68OrangeSunshine View Post
I've met Larry Page. Really nice guy. He used to be Pres of the Daytona chapter of Inliners International. He helped me [via emails] on tech questions when I was rebuilding my present 292 from 2002 -2005. The Man knows a lot about the Chevy L6 engine.
Larry also participates in this website as ''Twisted6'', usually on the 60-66 forum.
Still wondering if there's any advantage from having the primaries opening over 1-2-3 and secondaries over 4-5-6 with a carb-to-front orientation?
Likely if you where to measure you’d see the primary on a front facing carb is less than half an inch from a sideways set up.
The offy is a single plane style with plenum and runners all open.
All six cylinders see the primaries or the secondaries at wot.
geezer#99 is online now   Reply With Quote
Old 02-09-2021, 10:00 PM   #16
mikelcobb0@gmail.com
Registered User
 
Join Date: Aug 2019
Location: Cameron wi
Posts: 55
Re: Holley Carb adapter

My stock carb on my 292 is shot. What is available in larger CFM but without an Offenhauser intake? Is there something available to bolt on to the stock intake? Searching comes up with 4 barrels with rectangle mounts and 4 bolts. My stock intake is round with 2 bolts. Or am I dreaming?
mikelcobb0@gmail.com is offline   Reply With Quote
Old 02-10-2021, 12:24 AM   #17
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 6,980
Re: Holley Carb adapter

Quote:
Originally Posted by mikelcobb0@gmail.com View Post
My stock carb on my 292 is shot. What is available in larger CFM but without an Offenhauser intake? Is there something available to bolt on to the stock intake? Searching comes up with 4 barrels with rectangle mounts and 4 bolts. My stock intake is round with 2 bolts. Or am I dreaming?
Sorry, Mike. There's a reason a lot of us have gone to 4 barrel set ups. Unless you or someone-you-know is a wizard welding cast-iron manifolds, there are no 2 barrel options with the stock intake. Exception: there is a 2-into-1 adapter that can bolt onto the stock intake, but it's about 3-1/2'' taller at the base, and there are few 2-barrel carbs for that application. You want about 390 CFM at WOT for a 292.
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.
'68OrangeSunshine is offline   Reply With Quote
Old 02-10-2021, 12:34 AM   #18
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,494
Re: Holley Carb adapter

This one is about 1 1/2 inches tall.
Will run a 2gc.

https://www.tdotperformance.ca/trans...SABEgLHhPD_BwE
geezer#99 is online now   Reply With Quote
Old 02-10-2021, 10:02 AM   #19
old51sedan
Senior Member
 
old51sedan's Avatar
 
Join Date: Oct 2015
Location: Williamston, Mi
Posts: 869
Re: Holley Carb adapter

Quote:
Originally Posted by geezer#99 View Post
Likely if you where to measure you’d see the primary on a front facing carb is less than half an inch from a sideways set up.
The offy is a single plane style with plenum and runners all open.
All six cylinders see the primaries or the secondaries at wot.
Thanks guys for the replies. It's hard for me to believe that there's not an adapter plate made for this intake. It looks like I have 2 choices, buy a Clifford, or have an adapter made. Anyone want to trade there Clifford? My buddy from NY is here in Florida and he swears we will find an adapter plate. I'll let you know how the rest of the story turns out. I definitely want the carb sitting on the manifold facing to the front, I just think it's cleaner looking.
old51sedan is offline   Reply With Quote
Old 02-10-2021, 04:00 PM   #20
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 6,980
Re: Holley Carb adapter

Quote:
Originally Posted by geezer#99 View Post
This one is about 1 1/2 inches tall.
Will run a 2gc.

https://www.tdotperformance.ca/trans...SABEgLHhPD_BwE
OK. That's the one. I stand corrected on size. I have an Offy one out back, but I had a guy weld a plate on it for a Holley/Weber progressive 2-Bbl off a Vega, but the speed shop told me it would never have the CFMs for a 292, so I got a Holley 390 4-Bbl.
Thanks, Geezer.
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.
'68OrangeSunshine is offline   Reply With Quote
Old 02-10-2021, 04:37 PM   #21
mikelcobb0@gmail.com
Registered User
 
Join Date: Aug 2019
Location: Cameron wi
Posts: 55
Re: Holley Carb adapter

Thanks Geezer. I have it in a shopping cart. Now to find a 2 barrel at 390 CFM. Thanks!
mikelcobb0@gmail.com is offline   Reply With Quote
Old 02-21-2021, 07:32 PM   #22
mikelcobb0@gmail.com
Registered User
 
Join Date: Aug 2019
Location: Cameron wi
Posts: 55
Re: Holley Carb adapter

Please note that you must be a supporting member to post classified items. This includes but is not limited to What Its Worth, Want To Buy, Want To Trade, and For Sale. Please consider supporting the forum by subscribing. Further information on the subscription levels available are located here

If you need any further assistance with that please contact any Admin for help.

Last edited by LockDoc; 02-22-2021 at 09:36 PM. Reason: WTB by non-Premium member
mikelcobb0@gmail.com is offline   Reply With Quote
Old 02-22-2021, 11:14 AM   #23
old51sedan
Senior Member
 
old51sedan's Avatar
 
Join Date: Oct 2015
Location: Williamston, Mi
Posts: 869
Re: Holley Carb adapter

Quote:
Originally Posted by old51sedan View Post
Thanks guys for the replies. It's hard for me to believe that there's not an adapter plate made for this intake. It looks like I have 2 choices, buy a Clifford, or have an adapter made. Anyone want to trade there Clifford? My buddy from NY is here in Florida and he swears we will find an adapter plate. I'll let you know how the rest of the story turns out. I definitely want the carb sitting on the manifold facing to the front, I just think it's cleaner looking.
Just thought I'd give an update to this thread. After hitting most swap meets in the last couple of months without finding any such animal, I decided to take the original plate that came on the manifold to the welding shop. They welded the four original holes shut, I then marked it with the gasket and center punched the holes in the plate. Then drilled the holes, countersunk them and it was ready to bolt on. While out looking also picked up an adapter to a 2 barrel in case I wanted to go that way. Ended up buying a newly rebuilt Holley 550 cfm with electric chock, so I guess were ready to go.
Attached Images
   
old51sedan is offline   Reply With Quote
Old 02-22-2021, 09:12 PM   #24
'68OrangeSunshine
Senior Member
 
'68OrangeSunshine's Avatar
 
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 6,980
Re: Holley Carb adapter

I had my Holley 8007, 390 CFM turned so the primaries were inboard and the throttle lever over the Rear intake. Required some surgery.
What ever makes it work for you.
__________________


Every 25 years I like to rebuild that 292, whether it needs it or not.
'68OrangeSunshine is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:09 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com