95 Grand Prix 3.1 to 2002 Grand Prix 3.1

[revnrob]

Im considering getting a 95 Grand Prix in great condition with a dead 3.1,,, I can get a 2002 GrandPrix 3.1 with 4T65e tranny with harnes and computer with very low miles.
What will it take to swap the old 95 3.1 to the 2002 se 3.1?
Will the 2002 3.1 be a bolt in? Would useing the 2002 tranny fit and if so any benefits to useing it? If i have to swap parts what do I need to swap?
I have ben searching for someone that has done the swap but found nothing..

[jman093]

To get the transmission to work you'd have to do an OBD2 swap. Just swap the motor. Make sure the 02 motor has the EGR valve and tube to the manifolds on it. You'll need to swap that. If you want to use the better Multec 2 injectors on the 02 motor you'll have to rewire the injector harness or you can reuse your stock injectors. In either case you'll have to tune the PCM to get the fueling just right unless you swap the heads, rockers, injectors, and intake manifolds from the old motor to the new one since the 02 motor has larger manifolds.

[revnrob]

Thanks for the reply!! I can tune a Holly 4150 carb in my sleep but I have no idea where to look or go around here for PCM tuneing,I have no idea how to do it!!,,I doubt the old 3.1 has good heads to work with,,I was planning on useing the stock injectors and upgradeing to the 2002 injectors at a later date.. How would this thing run without the tune if I ran the old injectors? Would it pass the sniffer test?

[WrathOfSocrus]

The OBD 1.5 computer in a 95 cannot be tuned. I'm pretty sure a number of people here have done large port top end swaps on 94-95 cars without trouble. If you are just looking to get the car going for cheap then doing a complete tune up on the new motor and replacing the LIM (lower intake manifold) gaskets and the thermostat should Leave you with a reliable motor.

Doing a search for top end swap will pull up a number of threads dealing with the same issues you will encounter. Here http://60degreev6.com/forum/showthread.php/40366 is one for reference. The only difference for you is replacing the entire motor as opposed to just the top which in my opinion is an easier job.

EDIT - Since the computer cannot be tuned you need to reuse the old injectors and fuel rail (specifically the fuel pressure regulator). Also the rear exhaust manifold outlet may be in a different location on the new motor, so reusing the old exhaust manifold with some new gaskets will fix that issue.

[jman093]

Yep, I don't know how much off fueling is going to be off with large ports and old injectors, but it was way off when I large port swapped with the injectors. I had to lower the injector flow rate 20%.

[revnrob]

Thanks for the responses!!! Im only trying to achive a car that will be reliable for me,,not to worryed about haulling azz,,,,It just needs to stay running good and get deicent gas mileage,,,,My work is slow to the point of layoff statis and money is tight!!!!!!
It looks like my low mileage 02 3.1 might be sold,,,,,But I think I found a stock 3.1 just to get the car up and running,,,, I definetly will be on the seach for a low mileage 3100 for it though!!!
Thanks for the help guys!!!