Crank Seals !!
If you don't know how old your crank seals are, do your Blaster and yourself a favor and replace them. $20/30 for piece of mind.
While a leakdown test is great, it won't help you when your seal starts to leak 10 miles from nowhere.
I've worked on two recently that needed seals.
One the clutch side was in several pieces and had sucked the trans nearly dry. Luckily no damage.
The other had evidence of oil in bottom of case under flywheel. Didn't finish L/D as it was getting new top end (because of leaky seals=smoked piston) (flipper)
Be sure to clean crank and inside of collar and use some sealer on inside of collar, wiping off excess after install.
