If you've found a reputable shop that will do your machine work I'd let them go ahead and at least get the short-block assembled. Over the years I've assembled a pretty broad spectrum of engines without any failures, but for my own peace-of-mind, I chose to let a pro who had all the equipment do the disassembly, the block prep and machine work and the final long block assembly.
He took a definite interest in the engine (because I was paying him), made sure that he did it right the first time and I'm totally satisfied with the end result. Money well spent!
I've read too many posts from novice builders who missed some little detail and wound up with problems asking other novices for advice. That just doesn't make sense to me!
I provided my engine shop with the full-flow drilling instructions, timing cover bottom bolt mods, info on drilling the crank for a SBC bolt,cam gear installation tips and my shop manual just as insurance. His suggestions for getting a full dynamic balance and his attention to detail are evident each and everythime I crank it up and put my "old iron" onto the 21st century highway.
Dave
