Hi there Qewrty
When I bought my '64 TBird last year, it came with a 600 cfm
Holley. After I rebuilt it, the
carb worked fine. However, I had the opportunity to get a used
670 cfm Street Avenger
carb which I installed last month and I'm glad that I did. The old bird has a lot more power and better throttle response, especially when the secondaries open up.
I don't know whether or not you could go bigger than
670 cfm, to say 750 cfm. My gut tells me that with the stock
intake manifold, that would be too large and would actually inhibit engine performance.
Another bit of advice: whatever
carb you have, take the time to make sure that the throttle linkage is hooked into the right place on the
carb linkage so that when you push the accelerator pedal all the way to the floor, the
carb is opening all the way up.
By the way, a while back I called up the
Holley technical support guys and asked what cfm was appropriate for the 390. The guy I spoke with dutifully did calculations which he said indicated that all the engine needed was a 470 cfm
carb. Boy was he wrong!
Keep us posted on this please.
Doug
