Gtp engine
- Thread starter Jdpuller
- Start date
Kolton Lock
New member
98-03 should all be fine and dandy.
97S have a vacuum transmission which would be different.
Only things i can really think of, but I'm not a GP pro quite yet
97S have a vacuum transmission which would be different.
Only things i can really think of, but I'm not a GP pro quite yet
TLSheff
New member
97-98
99-02
03
Depending on which your is match accordingly. The Throttle Body is different on the 97-98 as is the supercharger a little. The 03s tend to fall into their own category. 99-02 is all the same and ideally what you want to go for. But keep in mind some other cars share the same 3800 SII motor. Regals, Bonnies, Park Ave ultras, etc... just make sure you get a complete motor.
I replaced the engine in my 99 GTP with one from a 97 bonnie. The supercharger is slightly different, has a extra vacuum tree that I just plugged off, and the Throttlebody was different but I used my 99 on in its place. The mounts out of the bonnie were all wrong but after replacing brackets and such it dropped in with no problem. For the most part the 97-03s are all the same bare engine wise, but some electrical connectors, mounts, brackets, etc... changed over the year. Just match up what you can and use parts you KNOW work when possible.
Also I would recomment pulling the top apart and replacing the LIM, rocker cover, throttle boy, supercharger, and other various gaskets before you put the motor in so you don't have to do it later down the road. The factory plastic LIM gaskets are know for failure and it would be an opportune time to replace while its out. Get the "problem solver" FelPro metal replacement Lower Intake Manifold gaskets and don't look back.
Good Luck.
99-02
03
Depending on which your is match accordingly. The Throttle Body is different on the 97-98 as is the supercharger a little. The 03s tend to fall into their own category. 99-02 is all the same and ideally what you want to go for. But keep in mind some other cars share the same 3800 SII motor. Regals, Bonnies, Park Ave ultras, etc... just make sure you get a complete motor.
I replaced the engine in my 99 GTP with one from a 97 bonnie. The supercharger is slightly different, has a extra vacuum tree that I just plugged off, and the Throttlebody was different but I used my 99 on in its place. The mounts out of the bonnie were all wrong but after replacing brackets and such it dropped in with no problem. For the most part the 97-03s are all the same bare engine wise, but some electrical connectors, mounts, brackets, etc... changed over the year. Just match up what you can and use parts you KNOW work when possible.
Also I would recomment pulling the top apart and replacing the LIM, rocker cover, throttle boy, supercharger, and other various gaskets before you put the motor in so you don't have to do it later down the road. The factory plastic LIM gaskets are know for failure and it would be an opportune time to replace while its out. Get the "problem solver" FelPro metal replacement Lower Intake Manifold gaskets and don't look back.
Good Luck.
Kolton Lock
New member
GP pro up there 
Kolton Lock
New member
Bill has the GM manual scarred into his brain lol
Slick2500
New member
Nope I have seen a few 98's with the vac tree. Look at that dude that broke up with his girlfriend and got drunk and bought a car, his is a 98 and his car has the vac tree.
Also the alternators on the 97-98 are different than the 99-02 cars as is the tensioner assembly, it has the lower coolant elbow built into the housing.
And not all 97 cars had the vacuum actuated trans, all the GT's and some of the SE's had it GTP's had the 4t65-e HD, but it has different cooler line fittings than the 98-02 cars.
Also the alternators on the 97-98 are different than the 99-02 cars as is the tensioner assembly, it has the lower coolant elbow built into the housing.
And not all 97 cars had the vacuum actuated trans, all the GT's and some of the SE's had it GTP's had the 4t65-e HD, but it has different cooler line fittings than the 98-02 cars.