Hey guys, couple of questions...

I currently have a 92 RS 305 TBI 5 speed car. I am wanting to swap over to a 700R4 with Dana's Shift Kit (I know thats blasphemy to some) . I am looking at picking up an 85 Trans Am w/ freshly rebuilt 305 TPI & 700R4, Posi rear and 4-wheel disc brakes. Guy doesnt have the title for the car and there is good bit of body damage so I can get the whole car for a song!

I am wanting to swap over the entire drivetrain with rear end. Am I going to have to do anything special to get my gauges to work? Am I correct in assuming that the donor Trans Am has a mechanical speedo and I have a VSS? Anything else I should know before taking this on?

 

The TA should have electronic speedometer, but your '92 will have a VSS buffer box, which the '85 won't have. The '92 will also have VATS, which the '85 doesn't. You'll have some things to work through, but nothing insurmountable.

The rest of the gauges should be okay.

 

Couldn't you take the tailhousing from the 1992 tranny and put it on the 1985 tranny and thus the speedo will remain indifferent?

If all else fails, I'd think soldering in the resistor for the VATS would solve that issue - then the no-start signal would never even get transmitted to the ECM (which wouldn't connect and/or understand it anyway). Maybe?

Would want to swap over the brake Proportioning valve for the rear disc brake setup.

New fuel pump for the TPI as opposed to TBI (I know TPI has higher pressure, but don't know if fuel pump is the same)?

I would think the rest is simple swap, plug, and play - with the wiring harness being the most difficult (in my world anyway, I hate wires)!

 

im looking to swap my 700r4 to a t5 u wanna trade?

 

Lol, only if you were closer

 

No. The '92 tranny is a T5, and the '85 tranny is a TH700.

No, VATS interfaces with the ECM, and the '85 ECM won't accommodate VATS. Better to just hardwire past the VATS.

That's a given.

Stock they are different, but you could either put the '85 TPI pump in, or just drop the '92 tank and put in a replacement TPI pump.

The wiring differences would be the most difficult part.

 

ill be moving to southern cali in like a month what yea say??

 

Cali? I live in Houston, lol

Thanks you guys for all the responses!

Is there a posibility of using the ECM off of a newer TPI setup and physically getting rid of the Cold Start injector? Am I correct in assuming that the 85 TA has a MAF setup and I would need the computer from a newer MAF TPI car?

I would like to keep VATS if at all possible.

Again, thank you, I appreciate yall's time and help!

 

It's possible. '89-up didn't have the cold start injector, but '90-up were speed density, requiring different TPI hardware.

 

Duh! I missed the 5 speed vs. auto.