1978 mci 8v-71 prison transport bus or '96 gillig?

[CarreAnn]

Can anyone please tell me if the '78 MCI DET 8V-71 is known for any common issues?

We are clueless at this point and will be looking at this year and make of bus. Is there anything we could specifically ask and look for while inspecting? We'll pay a diesel mechanic to take a look at it before a final purchase but I gathering some information for ourselves, in case we feel like moving forward with having it looked at by a mechanic.

Same question for a 1996 40ft. Gillig bus .. m11 Cummins motor Allison 5 speed

Any known issues for this year? I've been told no rust, and has styrofoam insulation.

Thank you!!