I saw a bonnet by banks eng. Had two holes for tubo, carb was holley, special carb was sealed to take pressure.Would work on any motor. Don't know if they still have these on market. To much compression, use 1975 - 76 heads. Also trying to get info on 425 tubo buick 1963. Would like to try and build one!
Gale Banks does almost exclusively trucks and SUV's these days. I'd be suprised if he has anything for cars still. IIRC the Holley DP with mechanical secondaries has been proven to handle up to 20+ psi without special sealing procedures being needed. Apparently the tolerances are are very good and this is why. Don't try it with an unmodified Q-Jet! I think you would be much better off building a 455. The parts are easier to find and cheaper. Plus there are a lot people who know enough about the 455 to help you out if you have a problem. Now if money is no concern, then by all means go for the 425. That would be great to see.
Are you talking about a box that completely encloses the carb, or something that replacces the air cleaner? Turbo city has a blow thru adaptor but I don't see a picture; http://www.turbocity.com/TurboAddOn3.htm I've seen a blow thru adaptor in the Turbonetics catalog but I can't find it on the website; http://www.turboneticsinc.com/ Here is a link with some info; http://www.turboforce.com/tech.htm The carb shop is one place I've seen on the web that sets carbs up for blow thru applications; http://www.customcarbs.com/ My 2-cent answer on the compression would be to stay away from the '75-'76 heads because of a lack of quench area. Use the earlier heads with low compression pistons.
