I'm building a 473ci for my 1946 Torpedo project. Ran out of money for the blower, now it's getting a dual quad. Any Pontiac guys out there familiar with the Offy 5499 compared to the Edelbrock P-65? I have one of each and need to make a choice.
I have used alot of both and they are about the same...pretty much. There are some diffrences though..First, there is a tall and low rise version of the Offy. The tall one looks like it has about an inch or so added to the top of teh carb risers. The usuall thinking is the taller one would make power a bit higher in teh powerband. Not a huge amount of diffrence for a street car. The Offys also take carb plates that usually come with the intake, but if yours is missing, can be a pain to find. (Offy does stock them new) Also, I don't think an HEI will clear teh Offy, but I could be wrong. But, you wouldn't want to run one of those ugly bastards anyway. The Weiand is a fairly low intake (which is fine) and the carbs are spaced very close together, which makes the spacing diffrent than most available air cleaners. In the end, they are mostly the same for a street car. I'd give the tall Offy the advantage on the strip, but they are all pretty even. If it were me, I would run which ever I could find. Here is the tall Offy. The short ones look the same but slightly shorter. Here is the Weiand. Good luck, -Abone.
Good info, thanks. The pic's help a lot too. The Offy I have is the 5499, which is the low profile 360 degree and has 1/2 carb spacers topped with 500cfm edelbrock's. I've heard the offy 360 dual quad manifold was better in concept than function and made a better door stop, because the 360 design only worked in concept. The same thread also said the Edelbrock P-65 was a much better dual quad for the Pontiac than the Offy. What gets me is the Edelbrock P-65 is also a 360 degree manifold? So how can the Offy be sooo bad??? Offenhauser always had a good reputation with the Pontiac engines. I hope more Pontiac fans chime in on this one.............
The 180 degree manifold is better for a street engine than a 360. And...... Offy 360 manifolds have some tuning and distribution issues. While they were an improvement over most old stock hardware, better manifolds can be had today. I would only use one if I had no better option. I had a new single-4 Offy 360, and for the reasons mentioned, traded it away a while back.
Yes, by all means, buy the one that's cheapest, not the one that will work the best for your engine. The Offenhauser intake for Pontiac V8, single or dual quad, won't make as much power as the stock quadrajet intake. Get the Edelbrock.
I got'em both. I thought the P-65 was a 180 manifold. I was reading the Edelbrock P-65 description and saw 360 degree one night and it stuck in my head. Late night in the shop with a few rum and cokes. Found the description tonight and it was a 360 degree view of the manifold. I guess drinking and research don't mix. Anyway, appreciate all the input. I'm going with the P-65, taking the 500's off the Offy and selling it. Thanks Guy's..............
GaronT, You made the right choice. The Edelbrock P65 will give you better all around performance as well as more low and mid range torque. The offy was good for it's time and still performs well but the Pontiac world of aftermarket performance parts has come a long way in the past 10 years. Not claiming to know everything but when it comes to Pontiac engines that's my deal. Been building and racing Pontiac's since 1979.
I've also got an Offy dual 4 bbl and the Edelbrock P65 and just looking at the restricted ports on the Edelbrock looks to be alot more restricted than the Offy. I guess it all depends on the engine and how you will be rev'ing it and what gears/cam etc. I bought an old original used P65 about 20 years ago and one of the 4 holes on the rear was so far off, the 4 bbl on the rear carb couldn't open. I called Edelbrock and they said they would fix it for free. I asked what they would do and they told me they would ease the edge to clear the butterfly. I would have thought the intake was set in a jig and all 4 holes drilled at the same time. It was so visually off, I don't see how this intake was ever run like that except you definately could tell it was run. I have about 15 different Pontiac intakes but I really love my 1966 Tri Powers out of them all.
Whippet, Not many intakes look cooler than a Pontiac Tri Power. If you had a GTO that was the set up everyone wanted. On the Edelbrock intake, the new updated P65B is the one to get for dual quads. That's the intake I was running on the 455 in my 61 Ventura. If you want performace and driveability on the street without sacraficing horsepower, that's the one to get. Now if you are more into the racing scene but still want to drive on the street, then the original Wenzler dual quad tunnel ram is the way to go if you have room under your hood. There were and still are a lot of guys using this one on the street. Just another option and Larry Wenzler still makes them. Here's a picture of the one I had on my boat engine.
I run an Offy on my 400 with 2 2895s AFB's and works good for just driving in the pits and on the track. Jon
Never ran a P-65 but used a Offie "low rise" on my race car...I was told by a guy in the know( Carb shop) that EdelB was not the way to go...Don't know about any late design ?? Ran the Comp 750 AFB's (dual) and response was GREAT !! Not to mention 11.19's with my old 462 motor.. My biggest thing is the Offie looks like the original spacing that Pontiac used for carb mount. EdelB got them crammed together and look like Chit IMO. I have run both the original Wenzler and now run the W Gutsram TR intake on my new 505 Poncho...all I can say is WOW !!! My 505 CI dynoed 813 HP with the "small ass" AFB's ... I am sure he has the room under hood with the older car... Picture below of TR intake..
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