97 to newer l36 engine/trans swap ??'s

**cavGTP** · 07-09-2009

Last year I bought a 97' GT with 188k miles for a good deal. Turned out to be a LIM failure. My first thought was to get a newer....about a 99ish motor to drop in it. I know 97 is the off year for the GP so I'm not sure what it would take to put in a newer L36. If I keep the 4t40e tranny, would I be able to use the 97 PCM and harness?....or should I swap to the 4t45e?......maybe the a GTP swap be more logical at that point?

The motor did leak coolant in. I thought about maybe cleaning it up and replacing the gaskets but i'm not sure what kind of damage has been done. Just wanting to get a good starting platform. Any input or advice would be greatly appreciated. Thanks!

**Bio248** · 07-09-2009

to use the 4t60e you need the 97 pcm. to use a 4t65e (which you REALLY REALLY should since its no longer vacuum controlled and a lot nicer) you need a 98+ pcm.

the only difference between the 4t65e and the HD version is the differential and axles, IMO not worth it. keep an l36 tranny for the good gearing too.

if you want more power, top swap an l36 block.

**blueguy** · 07-09-2009

Since it is a '97 you can find a '97 L67 motor and tranny and just drop it all right in at once

**cavGTP** · 07-10-2009

Ah yeah, I meant the 4t60e and 65 not 4t40 haha

Ok so i definitely need to get rid of the 4t60e. With the 97 L67, would my GT harness work, or would I need to get a GTP harness? I wouldn't need the axles cause the 97 GTP didn't use the hd tranny right?

I'm assuming a 98+ L67 would swap just like the L36 then (harness + PCM), except it needs the GTP axles...and the hd tranny of course. No need to re-pin or re-wire anything, unless I was trying to mod my 97 harness?

Sorry for massive amount of questions in my post, just trying to cover the various options depending on the deal I get with a motor/tranny combo. So, not a good idea to rebuild my current motor? MY buddy knows someone who can hone out the block for cheap.

Thanks for the help guys!

**Bio248** · 07-10-2009

97 GTP used the HD as well. only the 97 GT and SE have the crappy 4t60e.

do a 98+ swap of everything and dont look back (motor, trans, pcm, harness).

**cavGTP** · 07-10-2009

Ok, well I guess that takes care of it! Here's some pictures of it when I brought it home, oh and one of my 04 Comp G. Got a good deal on the 97...only $350...body is clean!Thanks again for the help.

**blueguy** · 07-10-2009

So you turned that $350 '97 GT into that '04+ Comp G GTP!?!? Man you got skillz

**grandprixgt** · 07-10-2009

Originally Posted by Bio248

to use the 4t60e you need the 97 pcm. to use a 4t65e (which you REALLY REALLY should since its no longer vacuum controlled and a lot nicer) you need a 98+ pcm.

the only difference between the 4t65e and the HD version is the differential and axles, IMO not worth it. keep an l36 tranny for the good gearing too.

if you want more power, top swap an l36 block.

so u think its better to keep the non HD 4t65e because i was thinking about getting the HD one before i top swaped