Synthetic motor oil
I have a 1996 Dodge Ram 1500 with the 318, was bought new by my Dad and has only 121000 original miles and never been abused and regular 3000 mile oil changes with conventional oil. Part stores here in NC are now phasing out conventional oil and pushing synthetic.
what are your thoughts on using synthetic at this point on a very well maintained truck?
The rear main needs replacement. Synthetic will aggravate the problem. Any sealant you use is just a band aid, temporary fix, if it works at all.