Ebay. Teds trucks, boyceequipment.com. Got 2 from boyceequipment.com myself. Look for a 6.2 engine as the 6.5 engines are way more expensive.
Again you may just need head gaskets or heads. Find out what side is causing trouble from removing the crossover and looking for bubbles and then go from there.
Either way, you can just pull that sides head and check the gasket, head for cracks, and check the cylinders for cracks.
Cracked cylinders aren't as likely in a 95 w/ 929, 141, or 599 block. Mostly a 97-00 506 issue. Also a cracked cylinder or block usually drains coolant onto the oil pretty fast
Get a full set of head studs or new bolts and both head gaskets. Change the other when convenient
Yeah that seems to be the first to let go since it has the driver side going past the rear 2 cylinders too. Too much exhaust back pressure. It's also the bigger pain to change with the bigger turbo manifold to pull off.
Its not that bad i put a new pass side head on my 3500 and it took about a day to do but that was with a few parts runs out to my 6.2-6.5 parts collection at my parents and with pulling the oil pan. Not to mentiom it was only about 25 degrees out and i didnt have any heat in my garage until i was putting it back together so i was moving rather slow.
Pulled the heads a couple of days ago and both gaskets were blowed at the number 1 and number 2 cylinders got them replaced and it fixed my problem. Thanks for all the help