I live in california and am doing a complete Trick Flow kit with Heads, manifold, rollerrockers, pushrods, manfifold etc. It is the kit you can get from SUMMITRACING. I also have all the other bolt ons too: MAF, TB, FULL EXAUST, UNDERDRIVE PULLEYS. I was wondering if I should change the oil weight? The motor has 106K miles, and I was also wondering if that kit passes smog. It says it's 50 state legal, but I am not sure. I know that the TB, UD pulleys don't say they will pass smog so do I have to put the stockers back on to pass? And what kind of performance upgrade will I get on a 5.0 motor 1990 MUSTANG? 3.55:1 rear end too with the King cobra clutch. thanks guys
eddie
eddie