[1973T/A]

In my 79 T/A i put a 73 455 in it and i have been trying to get it running good with that carb but with all that vac stuff on these later carbs just dont work with that older motor. I'm sure it can be done i just dont want to mess with it. Should i find an older rochester or carter? or go with an aftermarket carb? Its got 6x heads with 72 intake. I was thinking somewhere in the 800 cfm area. what do you guys suggest?

thanks
Pax

[2manyT/A'S]

ANY 1972 Pontiac quadrajet should work really good for you. (and relatively EASY to find)

You original 79 carb MIGHT be an 800 cfm,but the 72 will be a much cleaner fit.

[74Grandville]

your original carb should work fine with some tuning. get cliff ruggles q-jet book. your 79 carb is 800 cfm. if you decide to find another carb, look for one that was on a big inch engine. that way the calibration will be close.

[bobzdar]

Just plug all the unneeded ports, that's what I did...Carb doesn't need any of them to work.

[1973T/A]

The original carb had that spacer under it with more vac stuff. Like the brake booster. The 455 intake is alot taller so i decided not to put that spacer in there because the shaker would be to tall. But not having some of those vac lines hooked up will effect how the carb works.

[1973T/A]

I just think a 71 or 72 carb would look alot cleaner on that earlier motor like that.

[2manyT/A'S]

Originally Posted by 1973T/A

The original carb had that spacer under it with more vac stuff. Like the brake booster. The 455 intake is alot taller so i decided not to put that spacer in there because the shaker would be to tall. But not having some of those vac lines hooked up will effect how the carb works.

Sounds like your original motor/carb was a 301?

If you choose to use the the 72 Pontiac Q-jet, you can even hook up stock 72 choke.

You will need to find a 400 Pontiac (Trans am) air filter housing,as well.

I don't think 301 carb/shaker or air cleaner is the same.

[1973T/A]

Yes you are correct it was a gutless pos 301. Ya ive been keeping a look out for a 400 intake and shaker. So if anybody has a 72 Q-Jet that they wanna part with let me know.

Pax

[bobzdar]

Do you have a pic of the carb? In '79, it shouldn't have been electronically controlled so should be easy to adapt to any engine. I have 4 or 5 vacuum ports plugged on my '78 qjet with no ill effects, and the later qjets are 800cfm vs. 750cfm for the earlier. The only ports I'm using are the pcv on the front and the tree on the back for the brake booster and vacuum advance, all of the rest of the ports are plugged.

[1973T/A]

I took some pics but ill put them on here when i get home. With the brake booster and the tree they were both on that spacer. So were should i run the brake booser? If i remember correctly the carb is a 17059271 but dont quote me on that. Because i think that is the only 301 4 speed carb u could get... I do have a 73 455 carb i think that is a 7043262 or 7043265 i cant remember if its an auto or manual carb but the damn gas line inlet is stripped out.. and the guy i bought it from had the line JB welded into the carb..

Pax

[1973T/A]

here are some pics sorry it took so long.

[1973T/A]

any input?

[77 TRASHCAN]

Go to www.cliffshighperformance.com The 79 would be the best carb, my opinion, even w/ the added stuff, you don't need. You can install an electric choke on the 79 carb, not on the earlier ones..

The other carbs will work fine, also. Cliff won't steer you wrong. If you are capable of working on a carb yourself, I'd get the stuff that Cliff says you need and go from there (you have his book, don't you? )

[Grand73Am]

That's interesting. I didn't know a 301 q-jet had a spacer that it sat on. So, the spacer you removed had the vacuum tree on it? And there's no threaded hole on the back of your q-jet base to screw a vacuum tree into it? That is a bit of a problem since I don't see any other source for manifold vacuum on the rear of a Pontiac intake.

Maybe there is a plug there on the back of your q-jet base, that could be punched out to reveal a hole that can be used. If not, a hole could be drilled in it and tapped for threads that your vacuum tree will screw in to.

Of course, the other problem with the 301 q-jet is that it will be too lean for a 455. So, you'd need to modify the internals with a recipe from Cliff's q-jet book. So, as you assumed, it can be made to work, but it's more work. But, if you're going to rebuild whatever old used carb you buy anyway, it may be worth it to just rebuild the one you have and with guidance from Cliff's q-jet book, you could modify what you have.

There is an advantage to using the later 76-79 q-jets. Q-jets continued to be improved as time went by, so the later ones have all the best features, like the 800 cfm body, and the best APT system, and the ease of adding an electric choke. If you can fix that baseplate for a vac tree and richen it up, it will be a better carb than any of the old ones.

I just noticed you have a 73 455 carb already, except for the stripped fuel inlet. Cliff sells an inlet repair kit, at www.cliffshighperformance.com . You can probably fix it.

Also, your crooked air cleaner stud looks like one from a 403 Olds shaker, of which I have a couple . Does your shaker line up using that stud?

[2manyT/A'S]

The 79 301 4 bbl./shaker/air filter housing & intake was a bit of a unique animal & most of it was one year only parts. (the offset air cleaner stud is correct for 79 301 Trans am)
In 1980,all of these parts were revised to accomodate a "normal" type Q-jet,with different A/F housing & shaker.

I still say just get a decent "core" 72 Pontiac Q-jet",rebuild it & put it on.

The stock choke will match your intake,EVERYTHING will hook up properly and it will look GOOD. (those later carbs look like a mutated porcupine with all the vacuum pipes coming off them)
I guess you you could always decorate it with different colored vacuum plugs & if you removed your booster you wouldn't have to worry about WHERE to source vacuum for it.

[1973T/A]

Originally Posted by 77 TRASHCAN

Go to www.cliffshighperformance.com The 79 would be the best carb, my opinion, even w/ the added stuff, you don't need. You can install an electric choke on the 79 carb, not on the earlier ones..

The other carbs will work fine, also. Cliff won't steer you wrong. If you are capable of working on a carb yourself, I'd get the stuff that Cliff says you need and go from there (you have his book, don't you? )

Yes! i actually do have that book! haha

[1973T/A]

With that spacer that puzzles me the most its tapped in the back for the brake booster to screw into. so i took the spacer out bc otherwise the shaker would be to high. Where should i run the brake booster on this carb? The 72 carb is lookin pretty good.