1 3/8x.188 dom sleeved with 1 5/8x.125 dom. .313 total wall thickness. Bought the inserts from WFO Concepts. $14 ea. Had to machine the inside of the tube to fit the inserts. Inserts are 1 1/16" OD, tube is 1" ID. Also got the Superlift pitman arm. WFO machined it to fit GM DRE's. Arm w/machineing was $75. Trevor (WFO guy) also enlarged the taper in my ORD arm to fit the DRE's free of charge. Just need to pick up a 2wd box and the steering is done. Probabaly gonna make a tie rod from the same material. Progress is good.