sh*t!!! blaster forum is turning into banshee forum....hahahaha
if its an 89 it has an upper j arm instead of upper a arm. the hole in the piston is probly caused by detonation. so either the guy used low grade fuel (89 octane) or had some other sort of issue. thats not normal. now, once you get the top end figured out, replace that seal. its goin to cause an air leak, which may hav also lead to a hole in your piston. trust me do it right, do it once. less of a money pit that way.
you got it for free, so what ever you put into it, you'll most likely get out of it. if teh sh*t is donr correctly, they arent money pits. if they arent taken care of properly, any thing is a money pit in that case. if you need any help myself or 370 have a million banshees and can help you in any way.
the engines themselves are easy to work on. 370 has been inside countless banshee engines, from porting to full rebuilds, he knows them inside and out....
good free score, hope you get the issues worked out, and get to enjoying that banshee