Brian,
If your going to upgrade your rearend I would like to buy your 4:10 for my 49 3/4. I've got 4:57's now.
If your truck is an automatic then it is almost certainly a 4:10 ratio and some manual trans. also had the 4:10 but most were 4:57. Give me a shout if I can get the pumpkin from you. - Terry

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