2nd Gen Mini Tub Backspacing?
 

I'm in the middle of putting the rear suspension together but I need to give the wheel builders specs on backspace now.

1979 TA stock width rear, DSE tubs and Speedtech Torque Arm. Will be running a 18x12 with a 335/30. Fronts are 18x9 with stock subframe. Surely somebody is already running this set up and knows the backspace measurements. Any help?

Can't help you buto what size tire in the front? Subscribing to see everyone how this turns out would love to run this combo on my 73.

I did 6 3/4 with an 18 x 12, running a 315...butttttt, mine can come out at least an inchtoo narrow. I believe u can use this sizing cause mine can come out a lot more, HOWEVER, the TA's can withstand a wider overall (track width).

Best bet is too buy your rims FIRST, get close to the size, mock up, then build your reared to suit