Ok, so I had taken every bit of smog equipment off my car (89 350), then I moved and somehow not a piece made it with me. And I need to get it road legal again.

Question 1: 305 and 350 smog equipment is the same right? (smog pump, air injection, manifolds, tubing, piping, everything that has to do with smog control.)

Question 2: What years are compatable?

Question 3: I'm planning on getting a wrecked or junked car omewhere, stripping out the good stuff and selling the shell for junk. Does this plan make sense or should I piece it together from a junkyard?

Thanks! It'll be fun getting it back on the road, I've been driving my 06 Duramax CC SB in the mean time.

 

305 and 350 had different manifolds.

 

Thanks for the info Gord! Anything else bolt up or should I hold out for a 350 tpi?

 

I don't know for sure, but I'm pretty certain that the AIR diverter box (square thing on passenger side) is the same on all models. The AIR tubes that go around the engine to hook up the manifold AIR system being the same as well.

But yeah, the manifolds are definitely different looking.

 

You can use anything from any other serpentine car (88-92). '88 is slightly different, in that it uses a metal AIR tube around the back of the engine, but it will still work. The '89-'92 uses a rubber line.

The difference in the manifolds has to do with the single-cat vs dual-cat y-pipe. The 350 engines and the 305 engines that have dual cats have the same manifolds and y-pipes. Since you say your rear end has 2.73's (its actually 2.77 as the '89 IROC with a 350 engine and a single cat would have a 9-bolt rear end with 2.77's), you would have the larger manifolds but the single-cat y-pipe. You could get headers at the same time, instead of replacing your manifolds with another set.