V8 swap? Or turbo slant six?

A 318 can be had pretty cheap, sometimes even free; Thats how I got mine. Drive the six cylinder around for a while and save up cash for a 318 gasket kit, timing set, and a carb rebuild kit. Any 318 thats cheap, or again free, is going to need it.

You will need a transmission bell housing for the V8, the bolt patterns are different; you will also need either a V8 K member or an adapter kit, because those are different too. When I picked up my K member, it was cheaper than the adapter kit. I don't know what it is in your area, but look around at wrecking yards for parts.

There is a lot involved in a V8 swap, but it can be a lot better for the money, considering the equipment for LA motors can be found cheaper than for the sixes.