again x2 on pyroman's quote, except I am a 25 year ASE certified Master auto technician. ... IMHO do it once the right way the first time
I might as well tell my story. I baught my basket case '80 for 50$.
I didnt know a thing about mechanics, but I have always been able to look at gears and such, and under stand, so, I baught it, in pieces, with the motor together.
I checked compression, and one side good, none on the other. Peeked in the plug hole, and saw a destroyed piston.
heres what I pulled out.
after seeing that, It only made sense to split the cases, take everything out. I checked the bearings for smotheness, and used a case of carb cleaner to spray everything out, put it all back together with a 6th over topend, Baught a low mileage crank assembly for 80$, and it runs good. And most importantly, I KNOW all the aluminum grit is all out.
I'm no 30yr aviator mechanic, or 25 yr ASE mechanic, but I know when some thing is f'ed and should get torn down, and, sir, that motor there need torn down.
If you havent had one of these apart, dont worry, Its rollerbearings, and seals.
And you have us. Get out your wrenches, make some room, and lock yourself in the garage for a couple days.
Good reason for a taller 5th gear too.