Thread: ZZ572/620 Is stock demon 850 enough

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I'm working on installing a stock 572/620 hp Gm crate engine with a powerglide into approx. 2900 # Willys. Principle use will be drag racing. Is the demon carb big enough or should I be looking at bigger carb.

a stock out of the box 850 is small i used the 1150 on all my bbc s a re worked 1050 to a 1150 i have used the 9377 holley and the hp on all my bbc from 468to632 there could be better but they have worked good

I've always heard your ( start ) formula for picking a carb is CID X 2... but there are fudge factors.

I ran a HP 1050 holley on my 383 SBC. I would run at least that. Part # 8082-1

I ran dual 1150 on 522 bbc

In theory, yes. In practice, yes; that is what the engine comes with from GMPP and has demonstrated performance on the Dyno. It is a double pumper Demon but I do not know if it is indeed stock. It may have been tweaked for the 572 somewhat.

Kitz

Personally I would not run a demon on anything. I have seen to many people have problems with them. On my 383 sbc. I dynoed 750, 830, & 850 holleys. A 950 Quick fuel & the HP1050 holley. the 1050 made the most power every time. If you run a 4150 base intake with a 2" 4150 to 4500 adaptor plate it will work great. Out of all the combos on the dyno. On 4 different engine sizes the 1050 made a minimum of 35 HP to a max of 50HP. Thats on every engine we tried. 383,406,421 436 SBC & 408 Ford.