Just in case anybody was wondering what will fly in CA, my '90 5.0 5 speed w/: iron GT40 heads/E303 cam/MSD6A/190 lph pump w/ adjustable regulator/Mac shorties/BBK 2.5" Cat h-pipe/and Flowmaster 2-chambers recently passed California smog check with flying colors, notwithstanding the fact that it has 75k miles on the motor (and 180k on the car). In fact, the results were better than CA expects to see, with numbers far lower than the average they're logging for this type of car. The car has to meet HC; CO; and NOx limits, and my measured numbers were: HC 15ppm (121 max, 31 ave); CO 0.01% (0.76 max, 0.10 ave); NOx 96ppm (807 max, 237 ave). My last tuneup was about 10k miles ago, and all I did for this was to go for a ten mile high-winding blast to get the cats hot. Mine are technically all smog-certified parts either carrying Executive Order numbers or being classified as replacement parts so they damn well should pass, but the fact is that the car runs cleaner than stock. The BBK h-pipe has about 20k miles on it, but I put a big chunk of the clean numbers on the fact that the cats are pretty new, and that I run an MSD6A. Not the hairiest 5.0 out there, but it's a heck of a lot of fun. Just thought I'd pass this along for those who may be wondering about CA smog.