the least amount of problems. What are some ways to prolong their life?

 

The one with the lowest boost will last longest. There is a pretty tidy relationship between more boost, higher combustion temps and pressures, and shorter engine life. (Auxiliary injection might be worth mentioning because it cuts hard into that problem)

Among NA engines, the engine that is kept cleanest (least carbon) and is best maintained will last longest. Naturally, stock power levels tend to outlast ported and modified engines.

Dave

 

My GTUs is high bridgeported and should be completely fine when it comes to engine life. Only if you monster port or peripheral port do you need to worry b/c of leaks thru the water seals. Probably somethin you won't do anyway. Upgrade your apex seals, keep it carbon-free, and stick to the same clean burning dino oil. Your engine will last a long long time

 

you might be interested to know that the non turbo and tII 86-88 blocks have a serious coolant wall failure occurrence ... if you want me to get into the nitty/gritty i will... but for now perhaps consider this an exception to the rules above...

 

a lot of bridge ports can have bridge failure above 75,000 miles... hopefully your bridges were left FAT...