F100Panel,
I recently obtained a 55 GMC 350 COE and I think the engine and transmission (4-speed) are OK but would consider a higher speed (lower ratio) rear-end transplant. It now has the stock Eaton 2-speed rear end (its a 5.83-8.10 or 6.33-8.81).
Your engine/transmission should be strong enough (but maybe you need/want the power/oomph of the 350?).
Tim
