Thread: '97 GTP to '98 GTP drivetrain swap: Supercharger vac lines and misc. ?

I have a '97 mostly stock GTP with 210k on the clock now, original trans is getting weak but still very drivable for now. Car is my main DD but I have other junk I can drive while this is down. I just picked up the complete drive-train out of a totaled (rear hit) '98 GTP with ~140K on it and a trans that supposedly has less than 20k on a rebuild. The works is still together complete with rack, axles, brakes, etc. sitting on the subframe in the back of my truck currently. My 97 L67 still runs great, but I'm really tempted to just swap subframes and everything on top and keep the best parts! I am going to stick with the '97 PCM/wire harness regardless. Have a few questions: I just want to plan out the smartest "swap items" and try to get it all done within a day or so, other stuff can wait. I plan on replacing all leaking gaskets on engine/trans while everything is out and installing a Transgo shift kit in the replacement trans.

Supercharger: '97 has a Vacuum tree, '98 does not. Coupler in my 210k unit is very noisy but it works fine, pulley drop planned but not now. Can I rework the vac lines without drilling/tapping the '98 up unit?? Easier to just bolt on my old M90 for now??

Is there really anything else between the two years you would recommend changing out or checking? Injectors are the same correct?

Besides gaskets (not HG, not doing rockers) I think I'm going to toss on some cheap ebay headers unless anyone would recommend against doing so? I'm ok with a welder if they have minor fitment/sealing issues. I am on a budget but please chime in if you have any thoughts.

Input always appreciated!

Originally Posted by slick2500

Yes redoing the vac lies is easy, all you need is a vac t.

Easiest way is run a T off the Lim under the snout then run a line up to a T by the fuel pressure regulator then to the boost bypass or number 4 in that pic.

Thanks guys. Appreciate the pics/explanation slick! I see no reason why I shouldn't use the lower mile '98 blower. Anything else that needs to be changed?

Originally Posted by slick2500

You should be able to just drop out your old subframe and put the other one right in, you might have to change the trans cooler lines, the 97s used a threaded fitting and I think the 98+ cars used a quick disconnect fitting.

Thanks again. I have to change cooler lines anyway, no big deal. I'm probably going to run a aux. trans cooler and bypass the rad for now. Your m90 looks good in black, painted?