Leaderboard

reliability is only as good as your maintenance. keep up on the maintenance and you should not have any problems. I have seen several 3400's and 3800's with well over 325,000kms on them (200,000mi)

3.4 easiest bolt it in and go. if your not in a hurry do the 3.8

On that note, I would 3400 swap it, And if you want to on down the road, Turbo it.

3400 swap is the best for your $ 3400 will bolt in place of your 3100 and run on the same harness/ecm 3400 has aftermarket just have to look in the right places! 3400 can make plenty of power too just lots of people like the 3800 s/c because it came with boost from the factory and responds well to a smaller pully! a few guys with 3400's in j-bodys are making good power with boost check out this guy http://khturbo.net/rmtz24/RMTZ24.html 1989 Z24 5-speed '02 3400 V6, 10psi of Turbo Best 1/4- 12.41 at 112.8 328HP/352TQ to the wheels on a stock 3400 with a turbo! another J-body with a stock bottem end 3400 ran 12.21@118 two weekends ago, he has home ported heads, cam, centrifugal supercharger, headers and a few other mods! just giving you some ideas before you swap to a 3800!

3400 as far as simplicity will be almost a direct swap. there are a few things that need to be changed but it would be hands down the most straightforward a 3800 would be a little more involved, but again fairly straightforward.

x3

The question your asking is what would be the most cost effective. I would say swap another 3.1L. That would be the easiest, require less tools and know how. Ive done a swap with basic hand tools and a cherry picker. If your looking for more power, just upgrade the 3.1 components. Large port upper and lower intake manifolds, newer heads with rollerrockers, a TB out of a montana minivan. Upgrade your exhaust and air filter and you've got a scary 3.1L. If you swapped to another motor, you'd also have to swap the Computer and Wiring Harness which can be very scary unless you know what you're doing.

Either the 3400 or 3800 swaps wouldn't be very hard. Like Mitch R said, if you choose 3800(*cough* better) then just find a 3800 powered Lumina LTZ, and the wiring and swap would be pretty straight forward. 3400 would be easy too, since the 3100 is the same damn motor

3400 swap.

a 3800 out of a lumina LTZ would seem like an easy swap in your case, plus there is alot more aftermarket for the 3800. Plus the potential for a Turbo kit.