[jeffmort]

A 1350 yoke is already avaialble and is a common part. Actually we have 1350 yokes in a solid Spicer style1 or a custom quick release version. You just need to request which one you want when your driveshaft is being built.
Phil has a 1350 slip yoke and 1350 ujoint up front and has a "3R" style (not to common)ujoint in the back.
For the most part you will find 1310 ujoints as stock (sometimes a 1330). With that said, you can choose whicever size you want (1310, 1330, 1350). Of course you will need to change your rear pinion yoke to match your rear ujoint.