[Tom Vaught]

With a 66 GTO Hood you have a bit more clearance vs the normal hood. Not much though. Pretty much the same as a 65 Hood. Mike (MJM421) ran a Performaer RPM on his car with a 455 engine and liked it a lot but also mentioned that he had minimal hood clearance for a flat filter and had to use a dropped base air filter. Still not much clearance.

I also remember him saying that the RPM manifold worked very well on his STREET CAR (Mike drives his stuff) with a 850 carb. Might have worked slightly better with more air cleaner filter area above the top of the carb. The car would run faster at the track with the air cleaner off. So the RPM manifold in my opinion is a very good street manifold. I have run a couple of them over the years. That being said, I have also heard good things about the Kauffman Racing "Northwind" intake manifold. More hood clearance, very good power capability. Holley bolt pattern.

Tom Vaught

I believe that "JIM" at this business http://www.centralvirginiamachine.com/400resto.aspx sends stuff to Pontiac guys in Europe often.
He could easily get the intake from KRE for you and send it to you.

[Chris-Austria]

With the big carb and the RPM manifold I guess he liked to run the engine at higher rpm's? Sounds like a nice setup and I will check that Kauffman manifold as well, thanks for the info! I thought if the std. Performer won't make me lose power within my intended rpm range I will try this first (it's not expensive..) and check how I like it and how it works and if I feel the need for more power at higher rpm's I could check the hood clearance easily (RPM = +1,25") and make sure it fits before I mount it on my engine. (plus it's easy to sell a Performer manifold if I decide to change)

Anyone tried the Performer vs Performer RPM on his engine? If only looked at the performance from idle-5500 with both, will the std. or rpm be better?
And what about the spacer on the std. Performer, would that increase high rpm power a little bit?

I also found a formula to choose the correct carb size.. cui x rpm / 3456.. would be 730cfm on my engine and the Holley has 750 or 770cfm. Can't tell how much this formula is worth.. but also the Holley configurator said that the 750cfm carb would work fine for me. (Mikes engine 455 x 6500 / 3456 = 850cfm and my engine 435 x 5800 / 3456 = 730cfm)

[pfilean]

Over the years many things changed. Originally all three carbs had a 1 7/16 throttle bore. Then in 59 the end carbs went to a 1 11/16 bore which I believe was the same as many later single carb non-economy applications. Some parts interchangability is possible with the Rochester 2G and 2GC but you need to be carefull. Other changes were also made but things remained much the same until 1966 when the center carb also went to the 1 11/16 bore. If I remember right the total wide open three carbs would rate somewhere between 700-750 cfm. Of course the later would be on the higher end and you have a 1966. You can find 4 bbl carbs with higher cfm ratings but how much you need depends on your cu.in. and cam and what RPM you are trying to run. So if you really want to get higher CFM you may need a 4 bbl. Otherwise the only advantage I see (IMO) is that some 4 bbl use the same float bowl for front and rear throats (except Holley). That means that in most normal driving the fuel is changed more often and doesn't sit and evaporate leaving deposits in the bowl. I like to get on my tri-power some everytime I drive it to keep some fresh fuel going into the end bowls but it is hard to find a place to really open it up on the roads without seeing blue and red lights behind me.
For my money I like the three carbs but then I'm not racing either. But if I was I would probably go to 2x4. Which brings some additional problems. I just think you need a better carb man and some names have already been mentioned to you.

[tripwr1964]

I just think you need a better carb man....

2x

[Chris-Austria]

I found this article about the intake manifolds:
http://www.carcraft.com/techarticles...n/viewall.html

If it will act about the same on my engine, the real advantage of the Performer RPM will come into play above my intended rpm range, so I won't risk a hood clearence problem now. If I change my driving style or feel the need of more rpm's I can measure it and get a Performer RPM later. So thank you for all information, I'll try the std. Performer and report about the difference if I ever change it. The KRE intake looks nice too, but it's a single plane and intended for higher rpms. (like the Edelbrock TorquerII)

Now that I know which intake manifold I will use, can you tell me your opinons on carb choice? After calculating and talking to the mechanic there are 3 choices:

1. Holley Ultra Double Pumper 750cfm e-choke: http://www.holley.com/0-76750BL.asp
2. Holley Ultra Street Avenger 770cfm e-choke: http://www.holley.com/0-86770BL.asp
3. Demon Speed Demon 750cfm e-choke: http://www.summitracing.com/parts/de...20ve/overview/

Which one would you prefer?