quadrajet on a 250 inline advice

['68OrangeSunshine]

Studs are the way to go. And yes ears have to be trimmed, usually with a grinder.
Some pics of my 1404 on an Offy intake, the throttle cable and the throttle cable bracket, Jegs p/n 555-15152.
I'm using just a paper gasket under the carb, only spacer is the squarebore adapter, about 3/8". It's made of potmetal. A phenolic spacer might insulate the carb from heat in the intake.

[sixtyeightchevykid]

i dont think i am being clear enough... i have the stock exhaust manifold and the offy intake. stock the two manifolds bolted together, one bolt and two studs actually. the two studs are in the exhaust manifold and go up through the intake. those two studs were too long and they hit the adapter, no big deal i cut them shorter. but the issue is the mating surfaces(where they meet the head) of both manifolds should be flat, if i take a straight edge and put it across it i can see through. ill try to get a pic today

[sixtyeightchevykid]

here is what im talking about

['68OrangeSunshine]

OK. Sorry, I went with Clifford Research headers, Offy intake and a 390 Holley back in 1978. I forgot all about stock exhausts. I remember the Offy intake is an aluminum clone of the GM intake, except without pivot points for the [pre-'71] stock throttle linkage. Good luck.
I found out why the clutch on my '71 GMC would not disengage: the Z/bar is nearly broken -- the lower arm is almost torn off the central shaft -- only holding on by 5/16" and bent out of battery. I got it free, but only after unbolting the headers and the spark plug harness. Like Gilda Radner always said,
"It's always something."
If you must raise the carb, possibly a hot water plate under the baseplate, would give you clearance. With a stock exhaust you may not need carb heat. I don't use it because it's usually quite warm here in Tucson, but people in the northern tier swear by it.
If you have a mating issue with the surfaces of both manifolds not being at the same level, you might be able to cheat by using double gaskets and spraying both sides of each with Permatex Copper-Spray-A-Gasket.
Hope this helps.

[sixtyeightchevykid]

would you reccomend taking the manifolds to a machine shop and have them surfaced or whatever it is called?

[RichardJ]

I'd recommend finding out where the interference is. Remove the carb and loosen the bolts between the exhaust manifold and the intake manifold. The holes in the intake should be large enough to allow the two studs to move around so you can move the manifolds into alignment.
That's why I said not to tighten them untill you bolt the manifolds to the head. Snug all, then tighten. If at that point you find interference, then you deal with that.


I think i am being clear enough...

[sixtyeightchevykid]

there is not any interference. the exhaust and intake the flanges if you will or the flat part that goes next to the head are not even, i have loosened the bolts that hold the exhaust and the intake together. the difference is what i think too much... as you can see in the pics imagine the level the head and you can see daylight through the exhaust flange..

[RichardJ]

['68OrangeSunshine]

If the cast iron manifold is longer than the aluminum intake, have a machinist mill it even, [bring both pieces]. I wouldn't machine any "meat" of the Offy. You may want to upgrade to headers some time.

[sixtyeightchevykid]

'68OrangeSunshine, its the other way around, the offy has more meat than the exhaust.

i planned on langdons cast headers sometime in the future but its not in the budget right now..

[RichardJ]

Let me try one more time.
I'll type slow.

The gasket surfaces BETWEEN the intake manifold and the exhaust manifold are flat, parallel to each other and perpendicular to the manifold to head surfaces, that you are looking at and seeing as your problem.

It the two studs were removed, is there anything else that would prevent you from sliding the two manifold into a position that would line up the head surfaces of the two manifolds?
Interfer, interference, prevent, or what word do I need to use here to get you to open your eyes and look to see what is not letting the two manifolds slide across each other to correct the misalignment of the head surfaces.

The solution mat be that you have to drill the two holes in the intake to a larger diameter so that the studs do not interfere with the head surface alignment.

A rat tail file on one side of the hole may be enough. You may also have to relieve the hole on the exhaust manifold. It might also be that that is the only hole that is causing the INTERFERENCE.

[sixtyeightchevykid]

RichardJ, i see what are meaning and i understand. i apologize. it just seems like there is always something that gets me into a bind and i over think the solutions.. what i did is elongated the holes and that got me enough room to suck the manifolds to the head. i got the carb on yesterday morning and hooked up everything except the throttle cable,and vacuum advance, and i will need to re run the hot wire for the choke. i have to fab a different throttle bracket, the one i have does not go up high enough the cable would have to go through the valve cover..but i am making progress slowly

['68OrangeSunshine]

Originally Posted by sixtyeightchevykid

... fab a different throttle bracket, the one i have does not go up high enough the cable would have to go through the valve cover..but i am making progress slowly

Thats why I cut off the last 3/4" of the [Jegs p/n 51552] billet throttle bracket. It held my throttle cable at a place where it came over ( or around) the valve cover, and more importantly eliminated the need to hook a generic spring from the throttle lever to the brake master cylinder. I could see that as a problem later on. I kept the original manual choke cable and ran that over the valve cover forward of the carb.

[RichardJ]

My throttle cable is much like '68 orangesunshine has. I grabbed 3-4 cables of various lengths and a couple brackets from cars at the wrecking yard. The bracket was from the back of a QuadraJet and the cable I used was from a big car V8.
I had to make a few changes to the bracket to get a good angle for the cable coming over the valve cover. It bolts to both rear studs behind the carb and is very simple.

The choke cable is stock and comes around the front of the brake MC. It took a couple of redesigns to get what I wanted.
You don't want the choke cable to pull directly on the choke shaft. If you do and don't have the gas pedal down when you pull the choke, you will snap the end of the cable off in short order. The little arm I have that is on the end of the choke shaft is just floating there under the screw head. When I pull the choke ON, the only thing that happens is the long soft spring is stretched out. When I tap the gas pedal, the spring pulls the choke arm up and sets the choke.
I don't remember what linkage on the side of the edelbrock looks like as I don't have one here. What I have shown you may not be of much help.

In case you are wondering what is behind the choke cable, this Carter AVS had a vent tube that connected to a charcoal canister. I don't have a canister and the vent was in the way. I have the center cone from a stone fuel filter stuffed in there. About once a year I pull it out and clean it.

[sixtyeightchevykid]

here are a couple pics...

['68OrangeSunshine]

Originally Posted by RichardJ

My throttle cable is much like '68 orangesunshine has. I grabbed 3-4 cables of various lengths and a couple brackets from cars at the wrecking yard. The bracket was from the back of a QuadraJet and the cable I used was from a big car V8.
I had to make a few changes to the bracket to get a good angle for the cable coming over the valve cover. It bolts to both rear studs behind the carb and is very simple.

The choke cable is stock and comes around the front of the brake MC. It took a couple of redesigns to get what I wanted.
You don't want the choke cable to pull directly on the choke shaft. If you do and don't have the gas pedal down when you pull the choke, you will snap the end of the cable off in short order. The little arm I have that is on the end of the choke shaft is just floating there under the screw head. When I pull the choke ON, the only thing that happens is the long soft spring is stretched out. When I tap the gas pedal, the spring pulls the choke arm up and sets the choke.
I don't remember what linkage on the side of the edelbrock looks like as I don't have one here. What I have shown you may not be of much help.

In case you are wondering what is behind the choke cable, this Carter AVS had a vent tube that connected to a charcoal canister. I don't have a canister and the vent was in the way. I have the center cone from a stone fuel filter stuffed in there. About once a year I pull it out and clean it.

RichardJ: Thanks for the close up of a choke set up on a Carter AVS. I have an old AVS, came off a Mopar 440, that I was thinking about for a future project. Does yours have the old Carter 3-step metering rods? Edelbrock's Thunder AVS clone uses AFB-type 2-step metering rods.

[RichardJ]

It still has original 3-step rods, but there are a few parts from edelbrock that work.
I doubt you would like the large primary 440 AVS on a 292 if that is what you were talking about. For street drivability, even the 440 engine runs quite well with the smaller primary AVS from a 383 or 340.

['68OrangeSunshine]

Originally Posted by RichardJ

It still has original 3-step rods, but there are a few parts from edelbrock that work.
I doubt you would like the large primary 440 AVS on a 292 if that is what you were talking about. For street drivability, even the 440 engine runs quite well with the smaller primary AVS from a 383 or 340.

Actually, I was planning to rebuild my 454 BBC and resurrect my old '67 K/10 Suburban. But then I was laid off a couple of months in a row and the SUB fund evaporated. C'est la vie. I'm still thinking about a 383 project or just trying it out on my 350 in the '71 Jimmy. I found the AVS in a scrap pile so I'm not surprised that someone put the .100 deepwell jets in the secondary bowls and I think it has AFB rods. Dave Emanuel's book, "Carter Carburetors" mentions the 3-step rods as being good for mid-range performance, like when you're towing. Three step rods are unobtainable. Also the accelerator pump gasket is purple leather.

[RichardJ]

Here is another item you won't find on an Edelbrock parts list. Accelerator pump fuel inlet check valve.

['68OrangeSunshine]

I'll have to dig out my AVS and see if it's got one [or 2?] of those.
Currently the '71 GMC is in 'status down.' I found the mystery gripe: the upper arm on the Z-Bar was tearing it self off the torsion shaft -- only 3/8" was left still attached and that was bent 30* off line and hence the clutch was no longer releasing the flywheel. Anyway, I also had to detach the Hedman headers because the Z-Bar would not come off with out it. Also the plug wires had to be stripped out of the way.
Tuseday, I picked up the re-welded Z-Bar. I put a coat of HT Cast Iron Grey.
Work interferes with my maintenance and repair schedule, so I won't be able to put it all back together yet.
Damn lucky the '68 Stepside always runs, so I can get to work OK. L6 is the more dependable system.

[sixtyeightchevykid]

well i got everything on and put together. i messed with tuning the carb and took the truck for a drive. ill still need to do some fine tuning but its driveable now

['68OrangeSunshine]

Way to go!