I once had an S-10 (Well, Sonoma, but same thing) with the 4.3 in it. They don't make power, they shake, and they drink fuel like it's going out of style, but the OG 4.3 is about as unkillable as it gets. Hell, iron-block pushrod V6's were GM's bread an butter for the longest time. Everything from the 4.3 to the Buick 3800 to the 60 degree (3100, 3400) and even the High-Value 3.5 and 3.9 are all cockroaches. The current LV3 4.3L V6 from GM shares nothing in common with it's old Vortec SBC based counterpart outside of how it came to be. Where as the old 4.3 was a 350 with two cylinders lopped off, the new one is the Gen-5 5.3L with two missing cylinders and a slightly longer stroke. Results are 300HP/330lb-ft on E85 pump gas, or 285HP/305lb-ft on regular fuel. This is not a large enough deficit in power from the 2.7L turbo food blender to be discontinued in any guise, tbh. The engine is also low stress, so in typical GM pushrod motor fashion it'll undoubtedly run absolutely forever. A 4-cylinder full-sized truck should not exist. You have to turbo them to match the performance characteristics of a larger N/A engine, and in gas engines this adds unneeded complexity and unreliability. Diesels are a different story, of course. N/A diesel engines are just abysmal in every conceivable metric outside of longevity. Put the 4-bangers in the sub-compact and compact trucks and keep at least turbo V6's in full-sized half-ton.