[franky 455]

I asked this question in the race section, with one response, so i will give it a go here. Ok this is the picture, I have a 66 Tri-Power manifold with 3 different Rochester 2GC's that need restoring, I have no linkages or anything else tying me to them. Would I be better off with 3 x 350 Holleys? I am not interested in originality, they will be going on a mild 400 with a 4 speed in a 66 GTO, not originally a Tri-Power car. Does anyone have pictures of this set up?

[steve25]

I am not sure that 3 holleys in a row will fit in place of the Rochesters.And if looks/originality does not matter,than power wise a bbl on a E rpm performer is the way to go. Just the 4 bbl and aluminum manifold would take a bunch of wieght off the nose of the car in comparison to the trips and cast iron manifold!

[RandyW]

My buddy did just that about 25 years ago, he did some major butchering on the intake and used adapter plates. He works for me now, I'll ask if remembers exactly what he did and I'll post it here.

[Mr. P-Body]

Generally speaking, "adapters and carbs": BAD! All the stuff you need to correct the '66 setup is readily available from both PY and Ames.

If you REALLY want the three Holleys, get the BG manifold and use good carbs instead of those BGs that come with it.

Jim

[Tom Vaught]

While I agree in principal with Jim's (Mr P-Body's) comment, a few more bits of info need to be passes along before you condemn the Holleys on a pontiac manifold.

1) If you use the readily available "500 cfm" Holleys list # 4412, the
throttle blades/bores are EXACTLY the same size as the large 2GC carb blades/bores. The adaptor sinple changes the bolt pattern. Offy made great solid aluminum adaptors for years to put a Holley 2 bbl on a large 2GC Chebby intake.

2) Jetting for a Holley 2BBL carb is very easy to acquire in one jet steps whereas the Rochester jetting is average to poor in selection with average to poor quality control on the Non Rochester/Delco parts.

3) Floats, Power Valves, and Gaskets are same as Holley 4 bbl. A race bowl will fit on a 500 2bbl in every position on the 66 tri-power intake. The Mopar guys are stuck with Vac Secondaries and metering plates on the secondaries in most applications.

4) If you have Finned Valve Covers, Obrien Truckers makes great individual air cleaners for holleys that fit on the 66 Intake.

http://www.obrientruckers.com/Products%20Page.htm

You can have all of the benefits (minus the weight loss) by using the stock 66 intake with the Holleys and adaptors. I did my first Holley set-up for the 66 intake in 1977.

Tom V.

[RandyW]

I talked to Rich today, he basically did exactly what Tom described above and it was somewhere around 1978. The butchered intake I remember was an old Offy 2x4 intake that he made a half assed tunnel ram out of.

[Z Code 400]

Here's a cool adapter for better throttle response.....:-)

[RandyW]

Z, I'll keep that in mind in case I ever need to run my lawn mower carb on my Firebird.

[Jack Gifford]

Wow! That adaptor and one of those rumored "Fish" carburetors of yesteryear ought to get me 100 MPG with my 467-powered Suburban!