Big block 454 in my 98 1500 wt

Obviously all your intake, sensors, wire harnesses, engine computer and other modules, etc., will be useless, you could run some electronic controls but it'd be aftermarket stuff. They were making 1500's in the 90s with 454's in them, so you could pull a lot of parts from one of those if you can find one. You'll probably want to run a 4L80E tranny as that's what most of those used, so you have a ready made setup for the tranny. Really depends on how modern you want to make your 74 motor, as far as intake and electronic controls go. I would not use older transmissions like a 700R4, just because you'd have to work in a TB cable. I'm pretty sure you can find kits for upgrading an older carb motor to a newer truck. As far as fitment goes, again just find and use the parts from a mid/late 90's 454 truck.