I just picked up a LT1 and 6 speed trans from a 94 vette. I plan to put it in my 87 Iroc.. This was formerly a TPI car, but ive had many different motors in it since the original 305..I've cut out most of the original harness.. I am wondering if this is going to be a problem...I have all the aftermarket gauges and ignition system for the 350 i have in it now, which is carberated...Am I going to be able to use any of this...I have a 6AL box and all the little goodies that go with it .. I know im not going to be able to use my distributor.. Is there any reason other than the stock gauges and tach that the engine harness needs to to be connected to the car harness ? ...Any info you guys could give me would be great.. Ive been reading alot over the last few days and I couldn't find answers to my specific questions.. Has anyone done this same swap or something similar ? The LT1 came with the computer and harness and is fully complete as if it were in the car running.. All the accy's and etc. are on it... What is the bare minimum that this motor needs to run properly...Can I get rid of the power steering..I have a manual gear box in the car now... Thanks in advance, Artie

There should be no reason why you couldn't use what you've got. About the only thing I can think of that you might need to change is the fuel pump, you'll want a high pressure pump. The only other things that get connected are pretty much the guages and power wires for the engine harness. And manual steering is no problem. Probably the simplest solution would be to mount an idler pulley in place of the power steering pump.

Im going manual steering for a little bit, im too lazy to hook up my power steering. Only power steering I need is all the power I can must up, hahaha.

But really, manually steering isn't so bad, only at stops its a pain in the butt, but once the car is moving its all smooth.

Good choice on the Vette version. It will drop right in and all the wiring you'll need to splice into is at the C100 near the brake booster. The others will be inside. I have the same combo as you. You will need to have the PCM reprogrammed as the Vette programming is different and won't run stand alone. An f-body program will work just fine.

Will it run at all with the PCM the way it is ? ...Will a dealer reprogram it for me ?

Thanks, Artie

Also, Could give give me some kind of a list so I know what I need to splice in... This is my first go-around with fuel injection and I get lost in wires real easy... Any help to get me in the right direction would be a +


Thanks, Artie

Nevermind...I found all the info I was looking for...Just had to dig a little deeper...

A new question though... Can I put a regular 350 cam in the LT1... Whats the difference... ( I have a hydrolic roller cam for a 350 that i would like to install if possible and also a set of roller rockers )

Thanks, Artie

As long as the cam has the dowel pin hole for the optispark and has the same type retainer, you can use it. What cam do you have? Also, you can use any self aligning roller rockers, or non-self aligning with guide plates and hardened push rods.

Can anyone tell me what the VATS connector looks like on the wiring harness from the ECM...Cant find it anywhere


Thanks, Artie

Which harness are you looking at? The actual connector to the VATS module is black 16 pin connector up in the dash. However it is not going to be on the 4th gen harness. the C230 connector is one of the connectors that goes into the passenger compartment in the 4th gens, this carries the wire to the VATS module which connects else where under the dash. The C230 connector is a blue connector that I think is a 10 pin.

My car did not come equipted with VATS...But I'm under the impression that the new ECM has it... I'm trying to figure out what to do about this... Should I just send out the ECM to be reprogramed or is there a way around it..

Thanks, Artie

Yes...send out the PCM(whats it's called in regards to the 4th gen). Since you will have to do this anyway to get an F-body program written to it...it's only a few extra clicks for the programmer to diable VATS. Mine was done by Ion at www.madz28.com He is very reasonable and has an excellent turn around time.

i guess the 6speed is from the vette. i believe that makes it a zf6 and not a t56. its a great tranny but i dont think its a drop in install.
i just noticed because im looking for a t56 to go with the 95 lt1 i just bought. they're getting hard to come by and getting pricier.
in another month or so ill be going through all this lovely mess of wiring the motor to the car.

good luck

A Zf 6 speed requires a lot of modification to get into a f-body. You can sell it and easily net enough for a t-56. The ZF six speeds are real good manual trannies.

Do I need to keep the tube thing that runs from the back of the intake to the manifold (Looks like a emissions tube) Or can I cap it off at the back of the intake... Just wondering if I need to weld it into my header or not...

Just tell me if its better if I keep it or better without it

Thanks, Artie

I blocked mine off and passed the roller test just fine.