What HG to use Fel-Pro or OEM MLS???

I have a 94 SC motor around 400rwhp and have had no problems with my FelPros in the past. This motor has lasted 1 year 10k miles of tuning experamenting at 13.7 AF at WOT with 36' timing while overheating. But i see people are leaning twards the OEM Ford MLS gaskets. What is best for a car like mine? the felPros work but the MLS are 67 bucks if i get them for a 02 4.2. Is there a difference in bore size between the 3.8 & 4.2 gaskets?

Ford doesn't use a MLS gasket. You can get these from Cometic. Ford uses a composite layered type. I'd stick with the Fel-Pro's as they haven't steered many wrong. To use the Cometic MLS gaskets, both heads and block have to have a fine finish on them when being surfaced. So unless you can do that, go with the Fel-Pro's.

99 up 3.8s and 4.2s use MLS gaskets. Thats what im afraid of is my deck finish. I think i will stick with the Felpros.

I believe that as long as you keep the fire under control and the engine temps down the Felpros will do fine. I likewise have run lean for years before getting proper tuning software and have yet to blow one out. In fact when I pulled one head off recently for an unrelated cause (much drag racing and at least 20K miles), the gasket appeared as new. I am currently running 18psi on these gaskets.

My block deck is stock and it is atrocious so will not use the steel gaskets either.