I wouldnt bother rebuilding the 283 unless it's smoking or has a bunch of blowbye.
I've run a wore out 283 for about 10,000 miles over the past 8 years without a problem.
I recently rebuilt a 327, I used a machine shop that was connected to an autoparts store... pretty much everything the machinist needed was available through the parts store... They would even assemble the engine (for a price), but I assembled it myself.... and it even runs!!
