Join Date: Jan 2000
Location: Whitehouse, Texas, USA
The smaller Holley will give better throttle response, and probably be ok for everyday street driving, but will be too small for all-out performance on a 468 cid, 500 hp engine. I would keep the 850 on it, and tune it correctly. It sounds like you might have the wrong power valves in it, that are opening too early at idle and low rpm, and "sooting" the plugs. Carb size selection is really based on rpm useage, and engine size, and has nothing to do with mixture. Check your engine vacuum at idle,(in gear if it's an automatic), and select a power valve that is 1-1.5 sizes lower than your vacuum reading at idle. If you get an off-idle "bogg" when the throttle is cracked open, try larger size pump shooters. Hope this helps.
[This message has been edited by Peace69Z/28 (edited 07-22-2000).]