[nikivee1954]

Ok.. I recently purchased a Barry Grant Mighty Demon 800cfm Annular booster, mechanical secondarys carb to replace my worn out 850cfm Holley race carb on my 67 GTO.

After reading the instructions carefully I find that up to around 3grand the car seems to run fine. It's when I lay into the throttle that the car stumbles and misses bad. It is NOT an ignition issue at all. Something with the carb, I've adjusted that damn thing now for two days and still does not perform like my 850 Holley did.

What gives? Anyone have one of these carbs?

My engine

462ci + 0.030 over
87c E-heads with 1.65 Harland sharp roller rockers
CC292 hydraulic cam
4 tube heddman headers
th400 with 3500 stall 3:73 gears

Ran best of 11.5@118 on motor with holley carb. Now with the demon I'd be surprised if it got into the 12's!!!

Could I have a bad carb, or am I missing something here?

My holley has no power valves and 83 primary and 87 secondary jets If I remember correctly.