[SamsAutoParts73-87]

The 305 will fit, but you will need the flex plate / flywheel that fits it. You can use your wire harness but you will need to lengthen some of the wire to fit the V8. I believe the motor mounts are the same, but I think they need to be moved? You should really find a V8 radiator from the another 80s truck, or simply purchase a new one for your truck with a V8.

Most of the above changes apply to a 350 as well.

I'm probably forgetting something here, so maybe someone else can lend some info on the swap, I know its not a huge project since these trucks did come with 305s

In my personal opinion find a good running 350 and do the swap with that, I find the 305s are best used as boat anchors. Don't get me wrong they are a good running motor, but not something I would swap into anything, even if I was replacing an another 305

-Sam