swaps are very trustworthy as long as the engine hasn't been beaten or damaged.

i had my LS motor in my car for about 2.5-3 years and ran strong without any problems..except for a bent rod, which was my fault...

i now have a GSR motor and still feels very dependable. i've been driving it long distances and it hasn't given me any problems. (knocks on wood)

another reason i feel swaps are very dependable is because you get a chance to change out your engine mounts and do whatever needed maintenance to the frame with your stock engine out. this gives me a sure proof feeling that everything in my car is up to date and new.