I'd take a close look at Demon carbs. Call Don Gould at FBO systems in Beaverton Oregon (web site is
www.4secondsflat.com). He is extremely knowledgeable about carbs and engine set up, and will give engine set up information over the phone to your engine builder .. or you. AFR heads also seem to be a good investment and hold their value, and the engines value, and perform!! Have fun.