Well, my 97 Trep. is comming up on 200k miles and I'm ready to give her a new life.
It has the 3.3 in it now, but id love to put a 3.5 in it. I know its been done but cant find any info on it. I can do it even if alot has to be changed over for it to work, but any info on the matter would be great. I'd really hate to get in to it and find out alot more has to be done then i exspected and my car end up parked for weeks.
So what all is involved here? Do the engine mounts line up? Will the computer need to be swaped? how about exhaust - will the headers line up with pipes as is? I know they use the same trans. so no prob. there and I wont sweat the small stuff ( air intake and such ), but if you know it needs changed please let me know.

As far as computer - the only dif. ive noticed (looking through my repair book) seems to be that the 3.5 has 2 knock sensers where the 3.3 doesnt, so not sure if the wireing will be there or not. Also unsure as to weather useing the one ive got will mess up timing and/or fuel/air ratio. basicly have no idea if the use the same computer or not.

Thanx in advance.

 

See if you can find a whole parts car with the 3.5 in it andswap it out. You will probably need the engine compartment wiring harness for the 3.5.

 

I think it would be more practical to build the 3.3 a little. Not too much for aftermarket parts, but you could have a cam custom ground and mill the heads a bit to get compression up (will require intake milling and pushrod shortening). Port the heads & intake and port match the intake and exhaust manifolds to the heads. Get a high flow cat and good muffler to open up the exhaust. Run MSD8.5mm wires (have to use a universal set).