New Member, 1972 GMC 2500, Purchased New By My Grandparents

[harrydunn]

Greetings--

*First Post*

As of last Friday, I'm the proud new owner of my late grandparent's (91 and 99 years old) '72 GMC 2500 Custom, purchased new in March '72. I've been fond of it since I was a kid and always thought it would be great to own someday. 350/4bbl, automatic, PS/PB, factory air, original split rims, original paperwork still in the glovebox with Protect-O-Plate. It's not perfect by any means as it was a daily driver before being partially restored in 1988...and yes, the running boards have been taken off as of last night.

I do have a few questions.

1) Door locks work well except I am unable to lock the driver's side door with they key. It unlocks with the key just fine. I wanted to hold off on popping the inner door panel off to look at the mechanism until I talked to the experts.

2) Oil recommendations? I'm a Shell Rotella fan and run that in my '93 Land Cruiser (ih8mud.com member ). Your thoughts on weight? Synthetic/Dino? I'd prefer to run the same weight all year.

3) Transmission fluid recommendations? I don't think I'll flush a 38-year-old trans, just change the fluid/filter. Again, throw your recommendations on me.

4) Should I get the split rims off of it? I know they can be dangerous but I believe that is just while they are being aired up. How dangerous are they to drive on?

5) Pretty hefty rear main leak. How difficult to change? I'm sure I'd have to lift the engine a bit.

Pics from last Friday below. That's their '91 Lincoln with only 15,000 miles behind it.