Reply to "Demon 850"

Jim,

fyi, food for thought, the ramblings of a senior mind...

The 850 Demon would be equivalent to a 950 Holley. Demon & Holley measure their carburetor's flow performance differently, so the numbers are not directly comparable. Holley's are "dry flowed", Demons are "wet flowed". So Demons numbers are approx 100 cfm lower for an equivalently sized carburetor. Your Holley 750 would be rated as a 650 by Demon. So you are contemplating a carburetor that is 25% to 30% larger.

In the opinion of this old mechanic & hot rodder, for the state of tune your motor is in, it does not need a larger carb. For instance, going up to an 850 Holley "may" gain you 10 bhp and a few hundred extra rpm on top, but the trade off would be the loss of some throttle response on the bottom. I see this as a bad trade off on a street motor or a track motor. Accelerating from a stop light, or coming out of a turn, is more important than gaining power on the top end.

The acid test would be to test the car with each carburetor installed, on the same track, the same day, being driven by the same driver. I admit I could be wrong. However, in the absence of such testing, I would rather err on the conservative side.

Finally, also consider what you think is your motor's weakest link. Increasing carb size will accomplish little if the exhaust system is too restrictive. If a Pantera is running a factory exhaust system, including the GTS exhaust system, I can summarily say the exhaust system is too restrictive. Panteras need headers that dump into 3" collectors of reasonable length, connected to free flowing mufflers with 2 1/2" tubing.

An investment in the motor would be best spent on the motor's weakest link.

your bro, the cowboy from hell