Mark,
"Reading and learning" is the key. When I was a teen-ager, I rebuilt a VW engine, a Chevy 283, a Chevy 327, and did some major work on a MoPar 318. That was well over 30 years before I tried another engine. I rebuilt my M130 engine in my garage. The moment it started and ran was one of the most rewarding and joyful experiences of my life. I can still remember the feeling and the neighbors still remember hearing me.
I cheated on the cylinder head and found an experienced retired MB mechanic to help me. I did the bottom end by myself with advice from him and this forum. The big mistake I made was buying a bum donor engine from Star Quality. (I'll never do business with them again.) Even without that financial mistake, I would have saved less than $1,000 off of a Metric or Noel's rebuild. If I were paying for my labor, it would have been much cheaper to go with a re-man.
I used all new parts, including new valves, pistons, gears, etc. There were a few important tricks that I got from the pros. Like, how to trim the crank seals, and being sure to pump up the oil in the timing chain tensioner. It was a great, rewarding experience. If my engine blew up tomorrow, I would not regret having done it myself, but this time, I would buy the finished product from Metric or Noel's.
Also, look at your timeline. Decide how soon you need to do this. When do you think you'll be far enough along with the body to put the engine in? It sounds as if you have hundreds of hours of body work to do. Would it make sense to finish the body and then do the engine when the body goes to the paint shop? A rebuilt engine doesn't get better waiting for months on the engine stand.
With my limited experience, (and probably you too) the DIY process is a gamble and doesn't save much money. However, I get to feel good every time someone is amazed I did it myself.
Ray
'68 280SL 4-spd Coupe
