Im rebuilding a dana 60 front and a dana 70hd rear. Should I run 13-50's or 14-10's or keep my yokes stock. Truck is a 81 1 ton that will see trails and pave.

Run stock. Upgrade when u break.

Been running a 1310 front on my Dana 60 for a couple years now, aint broke it yet. Been running a 1310-1350 conversion joint on the rear for years now, ain't broke it either.

1350 are fine for 90%.

1350 and 1410 have similar strength anyways Same thickness cross section and same size caps) the bigger advantage is they ll run on a steeper angle.

I would run stock until you need it... When you change the cost difference between 1350 and 1410 isn't much so I would just go 1410 so you don't have to worry as much about angles. I paid 500$ for a thick walled (.188 I think) half ton FordCV/1310 shaft & yokes. However my .25 wall, 1350CV/1410 shaft & yokes was only 700$ each.

1350 and 1410 have similar strength anyways

Somewhere there is a chart compairing strength... It might be in Billavista's driveshaft article. As I recall a 1410 is rated only 10% stronger then a 1350 because the bearing surface is farther from the centerline of the drive shaft and therefore has more leverage and will last longer.

Whats stock for a 1 ton?

Whats stock for a 1 ton?

What do you mean? It's probubly what you have on them now???? 1310 front and 1350 rear was common...