[eyebuzz]

Thanks Ray and Longhorn - The differential seems to be the H052 (cover is round as a full moon). My hesitancy to switch the rear end comes more from locating and shipping a rear end (looking at the set up it doesn't look that hard to do). I'll think about it and compare to overdrive - see what's out there...so this leads to a few questions --- BTW - coil springs.

Overdrive:
1) Overdrive would just help out on the highway - correct? (solve two of my three concerns - hwy MPG and cruising...not city MPG)
2) From what I read it looks better, for the automatic, to replace the transmission - switching in one with a 4th gear vs. an external overdrive. Opinions?

Rear End Swap:
1) Any difference for a 72 pickup to a 72 Suburban (or even Blazer/Jimmy) in terms for the rear end - can I use one from any 3/4 ton?
2) For 3/4 tons what was the proportion of Dana or H052 differentials (rough estimate)?...very many Danas with taller than 4.11?

Thanks,
TT