Okay my Blazer is an 89, and I live in Jefferson County, so I need to pass the smog test, Grrrrr! I built an engine and I am a little unhappy about the outcome. Here is a description as best as I can type it..... 4 bolt main smallblock .030"+ flattop pistons Ballanced cast iron centerbolt heads valve job and stainless valves Comp Cams Xtreme Energy roller cam (lift .480/.487 dur @ .05 = 206/212 Comp Cams valve springs GM roller lifters Crane Gold Race roller rockers (1.5) Cloyes double roller timing set Edelbrock Victor Series water pump Edelbrock MPFI MSD billet small cap HEI distributor MSD coil MSD Offraod Ignition System MSD Super Conductor wires AC Delco plugs K&N X-treme air cleaner assembly Thorley Tri-Y headers 3" Y-pipe 3" Flowmaster 2 chamber muffler an engine oil cooler with GM thermostatic bypass/adapter. The tranny is a 700R4 built as bomb proof as can be. The gearing is 4:56 and the tires are 36" TSL Super Swampers. I barely slipped past the smog test, it runs okay, just had hoped for it to be a little stronger. I have thought about running a smaller exhaust to build a little more back pressure, and having the chip re programmed. Any other suggestion?