Suggestions on performance upgrades for 225

Thank you for all the great in-put and advice. The Clifford Performance package (intake, headers, 2bbl Weber, air cleaner) is only 1,300.00. I have a great muffler guy who isn't that expensive, either. I'd like to keep the slanty in the van to keep it original as possible. I have searched (South FL) for a V8 with not much luck. Though I do have a lead on a built/performance slant 6. I'll keep posting on the decision and the build. I'm really happy that I found this forum....super helpful!