engine swap questions
 

Son in law wrecked daughters 96 blazer LS 2x4. Destroyed the front clip, and twisted the frame.

We found a 98 LS 4x4 with a blown engine, and are getting ready to swap the 96 engine into it. I've done some swaps on older vehicles before, but need a few hints on what I need to be looking for.

98 RPO shows California emissions package, 96 is 50 state. Planning on using the pcm from the 96, but need to know what else I should be looking for.

Have seen on other threads here that the oil pan & pick-up may be different, and am prepared for that. will be re sealing the 96 engine -- has oil seeping from front seal, rocker arm covers, and possibly from rear seal. Otherwise, 96 engine ran good. Has good compression, good oil pressure.

Will I need to change anything in the underhood wiring harness?

Any other things I might have missed?

Thanks in advance for any replies!

You will not be able to use the PCM from the '96 as there were other changes & things that communicate with the PCM that didn't exist in a '96. The good news is that most all of the emissions stuff was not inside the engine.

You'll want to swap the oil pan & pickup as you stated. The 98 will have an aluminum oil pan that also bolts to the transmission.

Ok, thanks for the heads-up on the PCM.

96 appears to have the aluminum oil pan, with bolts to transmission, but looks like it may be deeper than the 98.

4L60E in both, and yes I know about the output shaft differences. Will want to keep the 2x4 tranny, is a fairly low mileage unit (117k) we just bought from a local wrecking yard. Came with a 90 day warranty, so I think I could assume it to be a good one. If the tranny in the 98 turns out to be not so good, I should be able to trade out the output shaft and extension housings between the two, being very careful to get the thrust bearings installed correctly. That is what I think happened to the old one in the 96. Bearings installed wrong, and soon destroyed the hard parts in that one. not even good for a rebuild.

Another unrelated problem we found: the wheels are vastly different between the two. 98 has shallower "dish" or offset than the 96. Daughter wanted to keep the rims from the 96, but I'm thinking that would be a no-go. Could cause wheel bearing issues down the road due to the differences.

They'll stick out further. The offset is different between a 4wd & a 2wd.

As far as swapping tailshafts... You should consider taking the trans someplace to have it done by someone that knows how it all goes together. It is easy to screw something up in a modern automatic transmission.