- Before/during assembly, you can't be too clean. Don't think a shiny new shortblock from Subaru was assembled with that in mind:
- Find the best machinist in the area/region, and keep him supplied with his favorite beverage, green fees, food, etc.
- Never spin rings on the piston.
- Clean your freshly machined cylinder walls with brake cleaner initially, then again and again (and again) with tranny fluid. Install rings dry as a bone. Learn to use a product called "quick seat" by Total Seal. It's worth the time you'll put into prep.
- Learn how the relationship between rings, cylinder finish and pistons work.. really....you'll never say your freshly machined cylinder walls are "clean enough" again.
- Find out where you're at with camshaft buckets before the final assembly of your heads...tell your machinist what the lash should be, and you'll likely never have to buy another bucket.
- Don't forget the PCV / scavenging system. I cringe when I read about people bypassing it and using only catch cans. I have a B15 that used 1.5 qts of oil every 100 miles, until I replaced the entire PCV system (the hoses looked great, but were occluded). Now its' usage is negligible.
- If the acetone / tranny fluid trick won't help you with the stubborn fastener, apply heat and wax (like you're soldering). The wicking effect (or capillary action) will draw the wax into the threads and the fastener will break loose.
I'll think of more as they rattle around.