65 Barracuda daily driver
great job pivoting and making it happen!
i'm a little unclear, did you use sealant on the stud as well as the helicoil? because it should be on both.
i would advise against putting alumaseal in the system, especially if you don't need it. all that stuff does is gum up the works. i would try everything on the face of the planet before that, including pulling the head and enacting a professional repair.
if you MUST use a sealer of that type, i'd suggest K-seal.