+1 on granny gear manuals being the best! I have the same trans in my '95 (5.61 first gear), and my '72 has an even lower 6.72 first gear. In low and first it is AWESOME!

 

I rarely put mine in 4lo although mine is auto trans. The owners manual does say not to go faster than 25 in 4lo. That is for the 1500's though. I am not to sure what the 3/4 and 1 ton's are capable of ion 4lo as far as speed.

 

Just an update. I have had the truck running and driving 4 wheel drive and 2 wheel drive with no problems for the last 6 months with no problem. I had it at the beach and climbing dunes and the drivetrain held up great. I did wind up replacing the power brake booster after that due to a leak but over all great truck. Now if I can only get a dash board that is not cracked.