I am buying my friends truck and it has a worn out 5.0 that won't pass smog but he has a 5.8 that someone gave him.
He tells me it is a simple swap and all I will have to deal with is the Y-pipe.

If I understand you right, then if the 302 is a 93 then I will need a new PCM and wire harness BUT if the 302 is a 94 then I am all good.

So I can drop the 351w right in place of the 302 with no extra charges?

 

well since you live in CA, it may not pass inspection with the swapped motor. your VIN is coded for the 302, same with your PCM, if you throw a PCM in with out having if flashed with your VIN, it throws a red flag. also the 5.8 puts out more gasses than the 302 so you wouldnt have much luck there... (i may be wrong, i live in a state where we dont have emissions.)