4.9 boosted just needs internals. No need to bore and not boring leaves the cylinder walls good and thick. They only need a good hone and checked to make sure they are still round. The transmissions are tough also. My father in laws truck is over 500k 4.9 and the only issue he had had is a new clutch in that time, trans output shaft seal at 400k (would leak into t-case), and had a bad run of slave cylinders when using aftermarket. (Slave cylinder is inside the bell housing) Went to a Ford slave cylinder and no issue since. Of course there has been normal stuff, o2 sensor replaced, egr replaced, valve cover gasket, oil pan gasket, but to me those are all wear items. The one item I consider wear that he doesn’t, is the exhaust manifold. At about 220k it cracked and started leaking. He threw a fit lol. To me, that is part of it. The amount of heat cycles it sees, it has to crack sometime. Especially being as it vibrates with the engine, has weight hanging off of it, etc. We put a pace setter header on it and it doesn’t leak to this day after that. Looks like crap and is rusted, but no leaks lol.
The trick to a 4.9 is finding one that has been taken care of or low miles. The head gasket issues are due to lack of coolant changes. The coolant becomes very corrosive and eats at the gasket. The exhaust manifold will more than likely need to be replaced.
His truck is slow being as it is a 4x4. Even the 4x2s aren’t fast. Nasty for 30’ lol, but the 4.9 is a torque monster. Not meant to be fast. Meant to pull a house down, and it has pulled a many of large trees down and around the farm.