I'd go the late model 304 V8 option. I started with a 308 out of a HX and the only thing that was useful was the rocker covers and intake. The block out of the HX was at 60 thou when we pulled the heads and it needed to be rebored and the heads where both cracked so I ended up with some expensive paper weights. The mate that is doing the engine said this was third early model 308 (pre-VN) that he had built this year that had needed a new block. The post VN stuff is 10 to 15 years younger and has less wear and tear when compared to the carby stuff.