I live in California and I have a 1989 Astro RS with a 350 TBI engine in it. At this point the engine is completely stock and must go through both the referee station to be checked for safety and then through a tail pipe smog test. The engine is a 1992 chevy 350 out of a silverado with 90k approximate miles. After I get it legal my plan is to rebuild and port and polish some stock TBI heads install an LT1 cam same as the Buick roadmaster had add some short tube headers (I got them for free) They are hedman 68600 shorty headers to be exact. 3 inch single exhaust all the way back through a sonic turbo muffler and high flow converter (brand new) I have added a 3 wire 02 sensor too. I plan on a better intake manifold too in the future along with bored out stock TBI and police car injectors. Do I need a new chip when this is done and does anyone here do them? my ecm/pcm is a 7747 and I have a couple spares as well as spare TBI units. I am welcome to any ideas. My plan for the van is long distant driving and towing a small camper at time. Thank you , Mark