is a holley 650-cfm dubble pumper carb to big for my motor 302 // 289 performer intake // ported stock heads // eletronic power fire distributor // headers // 2-1/2 dual exhaust to 2 40's flomasters // msd blaster 3 coil // T-5 trans ??
Probably not, but you'll need to find the right jetting. I have a 302 +.040 and run a 750 on mine. I do have a larger cam and aluminum heads though.
I had one on my car for a while. It wouldn't idle properly, and bogged when I put the foot to the mat. I tried jetting, but it seemed to run rich all the time, and adjustments just made it worse. Plus, it is a double pumper, and you might have cylinder wash with the second pump...not the best choice for stock street car.....In my opinion. That said, all engines are different, so yours may act better.
If you take the time to learn how to tune it properly you'll be fine. Personally I would get rid of the Performer intake and step up to an RPM.
the 650 cfm is fine but its the double pumper part that isnt the best for punching it off the line in a street car.steep rear gears help alot to get rid of the bog when you stab it at low rpm
Depends on how well you can tune a carb. With the right pump cam setting and possibly a decent spacer you can make them work. To the O/P.....what compression and camshaft are you using?
I don't understand why everyone makes a big deal about DPs on the street saying they bog and are gas hogs. No, they don't and no they aren't. The secondary pump doesn't do anything until you're past 1/3 throttle, which you rarely hit in normal driving. Before that they're just like any other Holley 4 barrel. Learn to tune!
The problem is that people tend to go to full throttle from a dead start - that will cause a bog and poor fuel economy unless the carb is tuned to perform at that level on the street or track. Blown 5.0, You are running a 1000+ cfm but your engine pushes a lot more air than a NA 302. If you were using a NA 302 with a stock cam it would be undrivable.
At idle i move no more air than a stock motor, at cruise i move no more air than a stock motor. I do think i can tune a 1000 cfm carb to be just as or maybe more street friendly than a smaller venturi carb due to the larger venturis. Especially a dominator due to its third circuit.
It's a custom carb so it's tuned to the application, but I know of a guy running a 950 cfm (actually flows over 1000 cfm) on his 289 along with "big" 192 Canfield heads and a reletively small custom cam. Drives great on the street and turns low 10s in the quarter mile. Just takes patience and knowledge.
