My friend is the first person I know of to put a Caddi engine in a trooper. He has had 2 4.9's which both died of holes in the block. He is also good friends with the owner of the top Cadillac repair shop in Phoenix and he always has a Cadillac in his shop with a hole in the block.

I just did head gaskets on a Isuzu 3.2 at 177,000 miles a Cadillac engine if it made it that long which it would not. Would have a hole in the block not a blown head gasket

P.S. I am not trying to just be down on a caddi engine because I'm jealous they are a far cry in terms of longevity from a Isuzu 3.2 or a Gm 60degree V6
you will no way get 275,000 miles from a Cadillac engine