IMHO there are several options. One would be a TLowe "3 barrel". Basically it's just a bigger Holley carb than you have with one of the primary barrels plugged. Another option, would be a Rochester Q Jet. By limiting the amount of secondary air valve opening the CFM could be adjusted. This was done from the factory on smaller engines like the 305 Chevy. By putting a screw in the air valve the CFM could be adjusted from 750 to well below 500. There is also a Carter AFB. There is a 500 CFM model and a 400 CFM model. The 400 might be hard to find. In the marine world, the 625 model was put on a 262 cubic inch Chevy v6. I don't know much about 302 GMC engines and their air flow needs, just throwing some ideas out there to think over. How about an Autolite 4100 for a 289 ford? I think that they are some where in the 480 CFM range. I hope this sparks some debate and exchange of ideas. Jay
