I have contemplated doing the very same thing with in the past month,can't find bearing spacers for this set up.Does anyone sell them??? Rod length is 5.7 but I think you would have to use the 302 piston and then measure quench area in case that decking would be needed,as there are differences in every block,though minute.302 pistons on e-bay are sometimes 'iffy' but some of the piston mfr's.do sell them new,though expensive! Conclusion I came to but havn't went thru with was when a local machine shop offered me a 327 block for $200.But then I took my 283 apart and saw that I had a cast crank(even though Mortec says it's forged,it's cast) so I don't think I'll do it.Good luck finding spacers,I heard they exist but I can't locate them?