John,
I myself have built a few of the 4.1's as well as an 8000 RPM 3.8 pushing 330hp. would love to see pictures of your intake set up, as I used gen 1 3.8 EFI parts myself in my last build.
cleaning up the stock heads with a die grinder, flow bench and a bit of time can really make the engine breath.
I would go with the M90 vs the M62 on the 4.1.
