Getting ready to purchase a used LT1. It's going in my '89 IROC-Z. I live in CA where the smog ****** are running about. What do I need to know and do when it comes to keeping the LT1 and camaro smog legal when going from the L98 to the LT1? Thanks.

 

Your going to have to retain all of the factory emissions stuff, which isnt bad at all on an LT1, the pump for the AIR injection is electric, it has one 5/8" hose that goes to each side of the motor, no tube going to the cat like a thirdgen, and the egr which taps into the manifold / header at the rear on the passenger side, the main thing i havent figured out with a cali swap is on headers, do they have to be for the motor, or will a set legal for the thirdgen work, and im not sure how much they will look into it, from what i've seen SLP and Hooker use the same CARB E.O. number for thirdgen and 4th gen headers, so if you bought a set of thirdgen slp's for emissions compatibility, had all the extra little air hookups welded shut, put the larger air hookups on the two front primaries like an LT1 set and the single one on the #8 primary for the egr, then had them ceramic coated a tech shouldnt know the difference, you could tell him they are for a 94/95 LT1 to match the motor since the E.O. number is the same, this also applies for hooker, also as far as i can tell the edelcrap headers are the same header for the thirdgen and 4th gen with the exception of the emissions hookups and Y pipe, so if you got a set of 4th gen headers and thirdgen Y pipe you'd be good also.

 

You have to take it to a "motor change" referee for verification. It will need to have all of the factory emissions equipment for the year the engine came from, or certified aftermarket replacement parts. Headers will have to be for the engine year, not the chassis year, if you use them.

I believe OBD II have to have the correct transmission as well. Careful on that one.

Your best bet would be to get as much information about the engine you're getting as you can, take your car down to the referee before you start the work, and go through it all with them. Your chances are much better going that route than they are trying to sneak something by them after the work is done.

 

Alright thanks for the exhaust help fellas. Now, when it comes to the computer stuff (VATS), what year LT1 would be easiest to work with? '93-'95, or '96-'97? Because I read somewhere they were different. Also, besides the 4 bolt main benefit of the corvette LT1, are there any other benefits, or would it be ok to just use a camaro/firebird LT1? Thanks a ton guys.

 

The only worthwhile benefit a vette motor has over the f body is the front driven accessories, you dont have to clearance the K member any for the a/c compressor (a non issue if going no a/c) otherwise your fuel rail inlet and outlet will be on the wrong side of the motor, and might cause extra hassle with the smog ****'s. I would definetly say get yourself a 94-95, probably stick to 94 since 95's there in cali were obdII, again check to see how a 95 would fly with the smog techs if it was an out of state motor so it wouldnt have been a cali spec one. VATS doesnt matter either way, its the OBD I / II that you need to worry about, and i'd say your gonna be best off with a 94 getting it past them, especially if you want to use bolt together stuff with the edelbrock components i mentioned (even though i hate their build quality and fit).