10 bolt to 12 bolt

[troyb_78]

I have an 84 c10 with 3.08 geared open 10 bolt. I am running a new 350 crate motor rebuild 700r4 and 31x10.5 tires. I do most of my driving from 45 to 60 mph with the taller tires I feel like I am really not getting the most of the OD. I would like to go to 3.42 or 3.73 ratio. I have access to a 12bolt out of a late 70 truck with 3.42s in good shape. What I am wanting to know is what is involved in doing a 10 to 12 bolt conversion. I know the u joints are not going to match up and I have heard the 10 bolt drive shaft will be short. Is it worth messing with or should just go looking for a 10 bolt with a higher ratio. Any help of advise will appreciated...