Welcome. FPA (Ford Powertrain Applications) and Sanderson make shorty headers. FPA is more expensive but it also a better product in my opinion. Good luck with the Cruis-o stall convertor. I purchased one from Broader Performance in Texas and tried running it with a 431 FE stroker. Either the motor was too much or convertor was garbage cause after 3 weeks there was filings in the tranny fluid and I ended up losing the entire thing less than a week later. C-6 is an easy swap and costs less than rebuilding a Cruis-o. Only draw back is trying to make the shifter linkage on a floor shifter work on an XL. Feel free to ask me questions via PM if you want to. I've redone everything you've spoke about with the exception of A/C. When it gets warm up here we enjoy it instead of trying to cool it down :^)

______________________________________

64 Galaxie 500 XL (constantly morphing)
FE 431 Stroker, C-6, Comp/Crane Roller assembly, FPA headers, Edelbrock heads, Zex n2o, Hydroboost.