[68c10airstream]

If you don't mind changing the rag joint with the box my favorite box is an early 80's c-10 (outside frame mount) 3.5 turn lock to lock and VARIABLE RATIO. I went to auto schooling in the late 70's (god i'm getting old, but my memory is still pretty good) and the variable ratio came about from a very quick box in corvettes. At high speed they would be hard to control and keep straight from being twitchy. So saginaw steering gear came up with variable ratio to give you the best of both worlds.

Here is the brief tech on it; The variable ratio is slower reacting at the center position, about 17/1. After turning the wheel about 1/4 turn right or left from center it quickens up to 13/1 for the rest of the turns. I have driven my 68 c10 with my 5.3 ls with my hydro boost conversion at 100 mph for 1/2 hour with no complaints.

My steering box was a n.o.s. 85 c-10 box, and i sourced a 95 v8 grand cherokee used ebay box and robbed the spool valve from it and installed it into the nos box for a firmer feel. I'm running 18's with about 9" tire foot print. 14" steering wheel (comfort grip gm wheel) and after my spring time front end alignment, after my hydro boost conversion the alignment guy said " god that truck drives great", like a late model, What did you do??.

Drop in for your 70?? Only issues will be lines and the fitting, and the fitting in the back of the pump that the line threads into. If you junkyard scrounge parts just get it all from the same truck, good to go. In about 74 gm changed from inverted flair to o'ring. If you step up to hydro boost the fitting at the rear of the pump is unique to hydro boost in the fact it has a bigger outlet hole.

And welcome aboard, this is a great forum!!