OK..so i just bought a non running siezed 86 iroc w/305 tpi..i purchased a used 305 tpi w/ a 700r4 trans from a buddy for only $200...If anyone can just throw a quick list together of all the modifacations needed to replace my stock 86 305 tpi with a stock 91 305 tpi w/7004r trans it would be aawesome!!..does anything need to be modified to get it running?, I'm very busy with work so I sent it out to a shop down the street to do the swap for me..Theyre giving me the old rig-a-ma- roll that theyre to busy to figure out the "little things" that vary from 86 to 91, any plugs, sensors, anything to swap the trans over to the 700r4.. I see diff ways of doing things on posts here so i was hoping someone had expirience and could tell me everything that needed to be modified..any help or input is GREATLY appreciated..Thanks!!

 

Take all of the TPI stuff off of the '86 engine down to the intake base, and all of the '86 accessories (alternator, water pump, power steering pump, AC compressor, front damper pulley). Remove the '86 engine from the car.

Take all of the TPI stuff off of the '91 engine down to the intake base, and all of the '91 accessories. Put the '91 engine into the car. Install the '86 TPI stuff and accessories on the '91 engine.

You can include pulling the '86 transmission with the engine and installing the '91 transmission with the engine if you like. The '91 TH700 was slightly upgraded over the '86 version. You will have to pull the tailshaft housings off and swap the '91 VSS stuff for the '86 cable drive speedometer stuff.

This is the "easiest" way to do this. You can argue that the '91 TPI system and the '91 serpentine accessories are superior to the '86 stuff, and I won't argue with you. But, unless you have the complete '91 TPI harness, sensors, and computer, and the complete '91 engine harness (from the C100 connector), and the complete '91 AC system (including hoses to the evaporator), you're asking for more work than you really want to tackle (or pay for).

 

The one comment I have to five7Kid's post is that you need to use the 91 TPI baseplate, but can use the rest of the 86 TPI stuff. The 86 still used the "old" bolt angle for the middle intake manifold bolts, so the 86 base won't bolt on without some slight elongating of those holes. It's easier to just use the base from the 91.

 

That's why I said "down to the intake base". Meaning, leave the base on each respective engine. Otherwise, I would have said "remove all of the TPI stuff...".

Sorry that wasn't clearer.

 

sorry, I missed that!