Phil-
Call Biggs, give them them all of the relevants details on your engine and they will build to suit. I have one of their carbs on my car now and I know someone else who does as well, and both mine and theirs were almost spot on out of the box and have been absolutely trouble free. Good support and prices are very reasonable as well. I hope this helps with de-modernizing your build.
http://bigsperformance.com/