I've found a 91 350SDL, 222,000 miles, leaking head gasket, which seams to be a problem with this year / model. It's not the year or engine I started out shopping for but I know the family's that have owned it for life so that goes a long ways with me. My question is if I do the gasket should I do the timing chain and related parts at the same time?

A. If it's still single roller chain

B. If it's already been switched to double roller
(haven't asked just found it today)

C. What else should I look for to be bad on this model?
(wasn't over heated) still runs good exhaust gas is getting into
coolant.

D. When the heads off should the valves be done as a matter of fact
or checked and worked as needed?

Any and all input welcomed

 

Already sold, guess it wasn't ment to be.