Don, if you want to keep the swap real simple, hold out for a 4.10 pumpkin. They are out there...just takes some patience and some searching. I've done it both ways...changed out the pumpkin on an Eaton HO52 from a 4.56 to a 4.10 and changed out the entire rear end. One is a Saturday morning plug and play job, the other is more involved.
The disadvantage of the Eaton is that the 4.10 rear end is still a low gear ratio if you do highway driving, and that is the tallest ratio available. If you want a taller ratio, you will need to do a swap.
If it were me, I'd make the decision based first on what I wanted for a gear ratio. If the answer to that question is 4.10, I'd stick with the Eaton for simplicity. If the answer is anything taller than 4.10, I'd take on the extra work and do the swap.
The pumpkin swap will probably cost you about $250 for the pumpkin itself and another $50 for gaskets and gear oil, so figure on about $300 total, more if you have to pay to have the pumpkin shipped. You can compare that to the cost of a replacement rear end and whatever it will take to do the swap.
Matt
