Steering box, what years fit.

[Hair]

I have a 1971 GMC, does only 67-72 steering boxes fit or will later years also bolt up and work?

[Hair]

Ok, been researching. I have an engine out of an 89 and the pump is an 89, so I need a PS gearbox from an 77 to 87 so the hose fittings will work and the later model box will also be a 3.5 turn, but should bolt up??

[kwmech]

up to 91 on the square burb and blazer. You can go a couple of different ways with this. One is to remove the 1'' nut from the back of the 89 reservoir and replace with the one from your 71 and just get a replacement box. (this may be the easiest) or get a later box from say 79-85/86ish that is Oring and have a custom line made that is O ring both ends

[Captainfab]

The '68-'86 C series and '87-'91 R series steering boxes are all interchangeable. In 1980 the fitting style changed from SAE to Metric with an 0-ring.