Question for the carb Guru's
 

I need to pull the trigger on a carb for my engine. Its a 439 bbc with a target hp of 530-550 hp @ 6000 rpms. I'm using the new AFR 265 ovals with a weiand stealth manifold, stainless marine exhaust, and crane ignition. Bob Mandara is doing the roller cam and has me pretty much talked into a prosystem carb.. The only issue is $$$$$. I can get a nice used HP 950 for about half the price. So my question is, would a Holley HP 950 be a could carb for this set up? If not what would you guys suggest. What kind of difference am I going to see with the prosystem vs the Holley? The prosystem still isn't out of the picture but I'd like to get on the water sooner than later.

950 seems too big .... what size did Bob Spec? He would know ...... .02

I cant see needing any more than 850 max or the venturi velocity is going to suffer.

The reason I say an HP 950 is that the way they are rated its closer to an 830 non HP holley or am I wrong on this. Bob didn't spec anything, he just said what i had was to small (780) and that he really likes pro-system carbs. I do agree that an 850 would be right but like I was saying above holley rates the two carb different. I believe one is a wet flow rating and the other is dry, so its confusing- an 850 in one isn't an 850 in another.

If you look at the thread I posted a couple weeks ago. JimV (Valako race Heads) and I flowed a Holley HP 950 against my old school Holley Barry Grant 750's. On the flow bench my 750's flow more % of air than the HP 950. My 750's supported 590HP on my 468 and I could have used a bigger carb. If you can only afford the HP 950 right now, get it and upgrade later. If you can borrow the HP 950 and plan on dynoing, bring them both and find out if it's worth it. I used my 750's cause that's what I had. A carb change is the easiest thing to change when upgrading power.

I also am using the Wieand Stealth and really like it.

http://www.offshoreonly.com/forums/g...-saturday.html

That was an interesting test. I was going to run a 780 holley that getrdunn has. I may still grab it and test it on the dyno and see what I come up with. A prosystems carb would be cool but I've just completely restored my formula and the money tree is running a bit low.

I'm running aprox. 600hp with a holly 800 double pumper

the 950 should work well, as it's not a 950cfm, common misconception....

What size is your engine?

Are you going to dyno this engine?? I am real curious about the those heads.

If I can swing it when all is said and done yes. I'm really curious as well what the real hp is going to be.. When I first started talking to bob m about this combo his initial thought was that we could make around 525-550 hp. There was a guy on the Chevelle web site that made 548 hp with those heads an RPM Air Gap and a holley 780 at 10:1 compression. The 750 was to small and the 850 was too big. His engine was a stroked 396 so it was within 4 cubes of mine. He was running an off the shelf cam so I would think that I should be very close to this.

Where abouts is northern MI that you live?

Onekama.