[bb400ho]

I have a 78 trans am. it was originally a 403 car. its now a Pontiac 400. the 400 i installed had a performer rpm and a holley dp on it . I want to change to a stock non egr manifold and q jet. Will any stock non egr manifold from 65 up leave the carb in the right position for the correct 400 shaker? also I put the y pipe and a magnaflow converter to the original exhaust. I think I would like to go with true dual exhaust. can I use the manifolds I have or do I need ho manifolds?
thanks bryan

[bs78ta]

Pretty sure the early intakes will swap as long as it is not a sd or ho motor. Stock logs will be fine they will just one pipe from each manifold all the way back. Need a crossover (egualizer, scavenger) pipe but it does not have to be an expensive x pipe setup unless that is what you want

[77 TRASHCAN]

What heads are on it?
The 68-72 intakes are the desirable ones. If you have later heads, the 72 iron intake fits better (has to do w/ the exh crossover sealing up)
Did you get a different shaker yet. The 403 takes a different one from the 400 Pontiac...

[ponyakr]

Originally Posted by 77 TRASHCAN

What heads are on it?
The 68-72 intakes are the desirable ones. If you have later heads, the 72 iron intake fits better (has to do w/ the exh crossover sealing up)
Did you get a different shaker yet. The 403 takes a different one from the 400 Pontiac...

HPP mag did a real good article on this subject. They recommended filling the blind hole in the late heads with furnace cement and smoothing it out level with the intake surface of the head. Then you can use the early intake and early style gaskets. I'd rather just run a Performer. It's lighter and less hassle. And there are plenty of cheap used ones floating around. But if you wanna run an early intake on late heads, here's a fix.

http://www.highperformancepontiac.co..._modification/

[rexs73gto]

If your going to put on true duel exhaust you will need atrans crossmember from a 74 fiberbird or T/A so the pipes will fit all the way back, otherwise the left exhaust pipe will be about 3 inchs lower then the right pipe. Or you can get an aftermarket crossmember from one of the aftermarket comp's. As far as a crossover pipe or X-Pipe you will only need that if you want it. I recommend them because they do give a little bit better power, & they sound better to IMO. If your going for better performance you would be wise to get a set of the Ram Air III ehxhaust manifolds or you can also go to a good set of headers but I like the manifolds. Better fit & they don't hang down as much. Also when you order your exhaust you can just order a complete set for a 70 with the Ram Air II engine & all will bolt right up the way it should. Of course you'll have the cross flow muffler if you do it this way which will make it sould very close to a 70 T/A then. Just read the artical on the intake manifold & it will be very easy to rmidey your problem, it's an easy fix.

[bb400ho]

thanks for the replies. it is a 400 from a member here it is a 78 or 9 400 from a trans am it has the 6x4 heads and a 2801 summit cam . he was running headers. I don't really like headers on a driver car. I thought I might be choking it with the y pipe and converter.
I have the shaker for a 400 and am in the process of getting the air cleaner base
thanks bryan

[Alvin]

FYI: Running an Edelbrock Performer on our '79 400 4-spd TA w factory Q-Jet and functional shaker (It's the non-RPM Performer intake.). Absolutely no clearance issues and you should be able to pick up a clean used one relatively cheap that fits w few easy mods. That should save you extra $$$ to buy a Pontiac engine shaker setup.
If you want new here http://www.summitracing.com/search/P.../Make/PONTIAC/

Edelbrock Performer Series Manifolds For Pontiac

INSTALLATION NOTE: For 1968-71 use our #8015 throttle bracket. For Trans Am use OEM 4-bbl. carb for Shaker Hood clearance. Choke plate included. Recommended intake gasket: Edelbrock #7280. HEI will clear. Manifold height: A-5.50", B-6.60" measured to engine block same as stock 4-bbl. intake; Carb pad height: 6.05". Port exit dimensions: 1.06" x 1.92". For the heights of all Edelbrock manifolds, please visit the the Manifold Reference Dimensions page.

http://www.edelbrock.com/automotive/...erformer.shtml

[burd]

I used a performer with the logo filed off, painted, it looks stock. it gets rid of the EGR and you can mock up the blue valve in the front for the shows, I also used HO ex manifolds. All the orig stuff is detailed on the shelf.
There was an issue with WOT, but it was fixed.

[Alvin]

Originally Posted by burd

I used a performer with the logo filed off, painted, it looks stock. it gets rid of the EGR and you can mock up the blue valve in the front for the shows...

Agree 100%

[Grand73Am]

Originally Posted by rexs73gto

If your going to put on true duel exhaust you will need atrans crossmember from a 74 fiberbird or T/A so the pipes will fit all the way back, otherwise the left exhaust pipe will be about 3 inchs lower then the right pipe.

Not true. It's not like the a-bodys. All Trans Ams have double hump transmission crossmembers all the way up through at least 1979. So his 78 TA crossmember is good to go.

[Grand73Am]

Originally Posted by bb400ho

I have a 78 trans am. it was originally a 403 car. its now a Pontiac 400. the 400 i installed had a performer rpm and a holley dp on it . I want to change to a stock non egr manifold and q jet. Will any stock non egr manifold from 65 up leave the carb in the right position for the correct 400 shaker?
thanks bryan

If you want to save some money, you could use a 76-79 factory 4 bbl intake. You just block off the egr and don't use it. Those intakes are dirt cheap since many people don't realize that they flow just as well as the older ones. Everything fits like original and they fit your heads without any hole filling or gasket concerns.

[Skip Fix]

Yep the 78 crossmember is OK for duals.

The 400 in the 81 car has 6x-4s cleaned up larger exhaust valves 2.5" HO/RA exhaust manifolds Summit 2801, Performer port matched and a 750 Q jet. Nice stockish motor. 14s. Did need a slightly looser than stock convertor to get movign good with the 3.08s I have.

[Alvin]

Yessir, diggin those 3:08 Rr Grrrrs for Flatlanders' high speed road crusin' here in the Gulf Coast area.

Your Summit 2801? http://www.summitracing.com/parts/sum-2801

[bb400ho]

I bought a rebuilt q-jet that has the divorced choke. the manifolds I have use the tubes for the choke. would the 72 have what I need?
thanks Bryan

[formula kid]

If I understand you, your manifold would be a 72. The carb you are going to use is a hot air choke that has 2 pipes one to the choke and the other to the rear of the carb. If this is the case the carb and the manifold will not work out of the box. You can get it to work by getting an electric choke conversion kit. Hope I understand the question and this helps.

[bb400ho]

what I mean is that the carb I bought has the spring style choke. I have a 77 or 78 intake that has the tubes for the choke. would the performer have the spring style? if so anybody have one they want to sell?
thanks bryan