I am about to do a gen3 lm7 into a 2008 silverado with a v6 in it, ive read its not possible but i dont think thats the case, it looks like all i would have to do is change out the crank to a 58x cam sensor to a 4x drill and tap the gen4 knocksensors to the side of the block and lay the harness down to see which sensors plug in and which dont to switch those out and plug it in to the ecu and to the fuse box and everything ive researched says it should work and the gauges and everything should work as well but idk