engine rebuild questions

IMHE 'nothing you have a spare part for ever breaks'.

Similarly, the time to start searching for a used engine is when yours is
still running well. When you think you do not need something, it seems
there are bargains everywhere. A well oiled spare engine (especially if you
have all the accessories like starter and alternator and coilpacs) in the
corner of your garage will just about guarantee that the one in your car
will run forever. When you sell the car you can always find someone who
needs your spare engine.

Having spares like coilpacs make problem diagnosis easier as you can just
swap components. When I got an error code, the Saturn dealer diagnosed
faulty coilpacs and wanted several hundred dollars for nonreturnable
replacements. I was able to install the questionable coilpacs on another
engine where they operated fine and was able to trace the problem to a $5
faulty plug wire. I was able to find a spare coilpac at a self serve
wrecker for $6 which will probably mean that none of mine will ever fail.

The local self serve wrecker has half price days every couple of months and
a complete motor is ~$150 (90 day guarantee). Last time I was there two
guys took an engine and transmission out in the morning and said they would
be racing (auto-fwd-4cyl-claimer class) with it that evening.

YMMV