Good luck with your new coupe!
Older Dukes seem to leak oil. I have replaced the crank seal and valve cover gasket, which fixed 95% of the problem. I still have an oil leak that only seems to manifest at high speed/RPM.
It's either a pan gasket or it's caused by blow-by forcing oil out of the engine. The cam cover is dry.
I still need to pressure wash, again, and see where it's leaking.
When I replaced the crank seal, I also replaced the timing cover. I looked at the cam gear while I had the cover off. It looked good as new. (It may have already been replaced. The car - which I only recently purchased - has about 150K on the odo.)
The belt tensioners are no longer available from GM or regular retailers. Rodney Dickman sells a modified tensioner that works perfectly.
I have heard of ignition coil pack problems, and problems with the internal balancer, but have yet to experience any.
Oil changes are a pain in the rear. The 88 Duke filter is in the pan. It's held in place by a big-azz plug that requires a special tool to unscrew.
[This message has been edited by Raydar (edited 11-08-2016).]