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 07-26-2018, 06:00 PM   #1
1971Stepside
Almost Satisfied
 
1971Stepside's Avatar
 
Join Date: Mar 2002
Location: Springfield, MO
Posts: 1,700
What transmission do you suggest?

I just purchase an LQ4 for my rebuild and I am excited about my decision. I had planned on a 454 with a 700R4, but the appeal of the newer motors is really there when it comes to dollars vs. HP.

I have a 3.73 posi installed in the 12 bolt and plan to run 18" wheels on the truck. The 4L60e is the obvious choice, but I hear it isn't very strong (I plan to swap heads/cam/and intake to get around 450 hp). The 4L80e is heavy and more expensive and sounds like a lot of extra work.

For those that have done this, what are your opinions? I'll post pics next week after I pick up the engine. The donor comes in next Wednesday and I asked to hear it run before they pulled it.
__________________
1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3000 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Other toys always push it aside, but one day....one fine day, she will be back on the road.

www.paypal.me/Cape505

"I can't complain, but sometimes I still do. Life's been good to me so far."
1971Stepside is offline   Reply With Quote
Old 07-26-2018, 06:16 PM   #2
greentruck
Active Member
 
greentruck's Avatar
 
Join Date: Feb 2009
Location: Ormond Beach, FL
Posts: 195
Re: What transmission do you suggest?

I would suggest going with the 4L80E. I don't think the 4L60E could take the HP that you're after for very long. It would be far less expensive to move your trans cross member back and shorten your drive shaft than to replace the 4L60E. That's what I did.
__________________
For some people driving is one long series of corrections...
greentruck is offline   Reply With Quote
Old 07-27-2018, 05:49 AM   #3
jessemthompson
Senior Member
 
Join Date: Nov 2011
Location: Raeford North Carolina
Posts: 786
Re: What transmission do you suggest?

4L80E is the trans you want. You’ll need a high hump for it, but it’s worth it’s weight. I would not put a 4L60E behind it. It won’t last long.
jessemthompson is offline   Reply With Quote
Old 07-27-2018, 07:54 AM   #4
Mike C
Registered User
 
Mike C's Avatar
 
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 6,671
Re: What transmission do you suggest?

Since you have the motor already, it's moot I guess. But if I were doing an LS swap and keeping the electronics I would be looking for a donor vehicle with either the 6 speed setup or 8 speed. Getting a transmission built is $$$ that it makes sense to get a donor with compatible trans in running condition.
__________________
44 Willys MB
52 M38A1
64 Corvette Coupe
68 Camaro 'vert LT1 & TH700
69 Z/28 355 12.6's @110
69 Chevy Short Step 4 1/2"/7" drop
72 Jimmy 4WD 4spd 4" & 35's
02 GMC 2500HD 4x4 Duramax
Mike C is offline   Reply With Quote
Old 07-27-2018, 10:09 AM   #5
1971Stepside
Almost Satisfied
 
1971Stepside's Avatar
 
Join Date: Mar 2002
Location: Springfield, MO
Posts: 1,700
Re: What transmission do you suggest?

It is hard to find an LQ4 around here that isn't in a 4WD donor. I had to buy the 6.0 and the transmission from two different donors. I looked at the 6/8 speeds and from what I read on-line is that they are not the best for "hot rod" applications due to difficulty in programming. Not sure if that is true, but I read it with enough frequency that I narrowed it down to the 60 or 80.
__________________
1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3000 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Other toys always push it aside, but one day....one fine day, she will be back on the road.

www.paypal.me/Cape505

"I can't complain, but sometimes I still do. Life's been good to me so far."
1971Stepside is offline   Reply With Quote
Old 07-27-2018, 10:29 AM   #6
jessemthompson
Senior Member
 
Join Date: Nov 2011
Location: Raeford North Carolina
Posts: 786
Re: What transmission do you suggest?

I have a 60 In my 5.3 swap and I’m afraid to do too much to the engine as I’m fearful the trans won’t last. I definitely wouldn’t have one behind a 6.0. A stock 80 will hold up to the abuse you throw at it.
jessemthompson is offline   Reply With Quote
Old 07-27-2018, 12:22 PM   #7
57taskforce
Senior Member
 
57taskforce's Avatar
 
Join Date: Jun 2014
Location: Farmington, New Mexico
Posts: 2,204
Re: What transmission do you suggest?

Quote:
Originally Posted by jessemthompson View Post
I have a 60 In my 5.3 swap and I’m afraid to do too much to the engine as I’m fearful the trans won’t last. I definitely wouldn’t have one behind a 6.0. A stock 80 will hold up to the abuse you throw at it.
This.
Keep in mind gm put the 85 which is just a slightly beefed up 80, behind the 8.1 in the 3/4 ton avalanche and suburban. I’m sure everyone is well aware how much of a torque monster the 8.1 is. I’ve got an 80 and an 85 both with over 200,000 behind factory big blocks. The 80 has been pushing 35s around for over 100,000 of those miles. Neither have ever been out or touched other than fluid and filter changes. They are quite reliable and plenty strong.
__________________
'57 3100 350/700r4 35x12.5's
'72 K/20 Cheyenne 350/SM465 in pieces awaiting ly6 6.0 swap. http://67-72chevytrucks.com/vboard/s...d.php?t=662879
'98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6"RCD 315/75/16's
'01 Suburban LT K2500 Vortec 496/4l85E 240,000 and counting- drive train still all original.
57taskforce is offline   Reply With Quote
Old 07-27-2018, 01:11 PM   #8
RustyBucket
Registered User
 
RustyBucket's Avatar
 
Join Date: Jul 2009
Location: Space Coast, Fl.
Posts: 820
Re: What transmission do you suggest?

Just for info, I've had an '02 GMC 4dr. 1500HD since it was new. 6.0 eng., 8 lug wheels. I think, but I'm not sure that it has a 4L60E transmission. 200,000+mi. and it's towed a lot, boats, campers, open & enclosed car trailers and KNOCK ON WOOD it seems to be fine. Good shift, fluid looks & smells good. Has a trans. temp gauge which I watch but it's never run hot even towing heavy stuff.
__________________
Dad always said, "Son, WISH IN ONE HAND, and ......."
--------------------------------------
--------------------------------------

'71 GMC 1500 SUPER CUSTOM short/step, orig. dk. blue, 350/700r, ps,pb, A/C
'72 Blazer 2wd, ochre & white, 454, tremecTKO 500 5spd. ps, pb, A/C, tilt
'66 Plymouth Belvedere City of Miami cop car clone

'70 Nova 406"sb, 13.5-1, solid roller, Brodix, p.glide/t.brake, back halved, 9" Ford, spool 4.88, cage,ladder bar/coilover, 10.5 tire....... SOLD!!
'67 C10 short/step side mount spare -- shop ornament, needs resto.... SOLD!!
'72 Jimmy 2wd, 350/350, ps, pb, fun driver, lots of bondo & a shiny red paint job..... SOLD!!
'69 Nova 350, 4spd, A/C, ps, p.b, needs resto...SOLD!!
RustyBucket is offline   Reply With Quote
Old 07-29-2018, 10:11 PM   #9
ZEKE68
Senior Member
 
ZEKE68's Avatar
 
Join Date: Jul 2012
Location: Space Coast, Florida
Posts: 347
Re: What transmission do you suggest?

4L80E fit in my truck behind a big block on stock mounts with a low hump. I am not sure if the LS engine position will work with the low however.
__________________
1968 SWB Step Side, Big Block, 4L80E , installing
ZEKE68 is offline   Reply With Quote
Old 07-29-2018, 11:01 PM   #10
weq92f
Registered User
 
Join Date: Oct 2016
Location: Dallas Texas
Posts: 1,046
Re: What transmission do you suggest?

Thank you Sir.

Quote:
Originally Posted by ZEKE68 View Post
4L80E fit in my truck behind a big block on stock mounts with a low hump. I am not sure if the LS engine position will work with the low however.

-klb
__________________
67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi
07 335 sport turbo 6sp
94 Trans Am GT LT1 6sp posi -- sold after 22yrs
99 540 sport V8 6sp -- sold
73 240z L24 4sp -- given to friend
68 C10 step 350/350 3.73 open -- sold
weq92f is offline   Reply With Quote
Old 07-30-2018, 09:22 AM   #11
1971Stepside
Almost Satisfied
 
1971Stepside's Avatar
 
Join Date: Mar 2002
Location: Springfield, MO
Posts: 1,700
Re: What transmission do you suggest?

I bought a 4L80e. Cab is already a high hump. May change out the transmission cross bar. I pick up the 6.0 and trans this Friday. Thank you all for the advice.
__________________
1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3000 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Other toys always push it aside, but one day....one fine day, she will be back on the road.

www.paypal.me/Cape505

"I can't complain, but sometimes I still do. Life's been good to me so far."
1971Stepside is offline   Reply With Quote
Old 07-30-2018, 09:44 AM   #12
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,032
Re: What transmission do you suggest?

I have the 4L80E. They're big (like a TH400 that our trucks came with though) and heavy like a (TH400) but they're strong as heck and have a great overdrive.

I made sure to get a STOCK rebuild with a STOCK converter as I'm not racing it.

You have to solve the speedo issue as there is only electronic. You can get a box that drives your speed cable electronically for about $600, but you can get an aftermarket tail stock with the speedo output cast into it for $695, and as brutal as that is, that's how I'd go.

Then's its just your standard swap - need a controller, length will be a little different, etc.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 07-30-2018, 04:48 PM   #13
1971Stepside
Almost Satisfied
 
1971Stepside's Avatar
 
Join Date: Mar 2002
Location: Springfield, MO
Posts: 1,700
Re: What transmission do you suggest?

Can I run a modern speedo since I am building this thing from the ground up anyway. I wasn't planning to run the stock gauges.
__________________
1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3000 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Other toys always push it aside, but one day....one fine day, she will be back on the road.

www.paypal.me/Cape505

"I can't complain, but sometimes I still do. Life's been good to me so far."
1971Stepside 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 06:59 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com