I have a 305 TPI in my T/A right now. I was planning on getting a crate Zz4 motor but want to know what can stay in the car and what will have to be changed. Could I use my TPI? What would the Zz4 bring my e.t. to?

 

Your TPI will work but don't use it get high flow stuff, the stock TPI will kill your power. Get an Edelbrock or Accel base and some good runners. I think the 87 is the same setup as far as the AC compressor, I had to drill and tap the pass side head for the AC bracket. A high flow base will bolt up easy (they are drilled for both old and new heads ZZ4 is old style). Other than a new water pump and other little stuff (things you can't plan for but will need whenever you do a motor swap) you will need a new chip and my car is SD so I don't know if there is any need for a new MAF (I don't think so). Many will bring up the EGR (ZZ4 heads do not have EGR passages but you can't tell when you look at the motor with the manifold on) issue but it is really not an issue I had the EGR turned off in the PROM and left it on the manifold and I pass inspection with NO problems.

The swap is not bad and is worth it. But take my advice and get a HOT cam before you install the motor, I was told I would want one and did not listen and now I have to do it after the fact and it is a pain in the ***.

Also you trans may be an issue down the road make sure it is good shape before you go adding a bunch of power.

 

I forgot one more thing you will want new injectors, I and others have used SVO 24# with good results.

 

The '87 is not the same AC setup as the '91.

Everything else he says is true, although a AFPR may help you run your current injectors: does for a bud here, but altitude may contribute some there - his mods are much more extensive overall, like ZZ9 cam w/1.6 rockers, bunches of porting, shaved heads, and he still gets the better performance out of 19 lb injectors than 24 lb-ers.

For the EGR, get a Vette-style base, which has the port for plumbing exhaust gases from the header to the intake.