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?