[dmjlambert]

My vote is try it since you already have it on hand. Plug the return line. I have a 69 with fuel pump and tank not having a return line and haven't had vapor lock and I run with gasohol. But I have a Quadrajet and ram horn exhaust manifolds and clutch fan, which may be a completely different setup. 7.5 psi is high to pair with some carburetors, but a regulator would probably solve that if needed. Now that I type this I better knock on wood and hope I don't start getting vapor lock.