Vern, actually you did not clarify if it was original or non original power steering. If you plan on putting that trusty old 261 in your wagon, excellent choice by the way. It is real easy if you utilize the original type power steering. It is the same as the Chevrolet, very easy to find used setups and they now sell complete repro setups. The only thing they do not repro is the special generator that has the spline in the back to mount the pump behind the generator.  The frame has all the dimples that tells you exactly where to drill for all the required brackets under neath. The generator/pump combination has no special bracket or no added bracket. I converted my 1957 Pontiac from "Strong arm" steering to original power steering and it was real simple as long as you have all required parts including the special pitman arm. By the way this is obviously for the Canadian Pontiac, the American Pontiac is totally different. Use a new repro assist ram because they have stainless steel rod not the chromed rods that the originals had. The originals were prone to leak so use the upgraded assist ram. I got to warn you though none of this is cheap. Especially if you are going all new repro, but at least you do not have to hunt except for the special generator. If you need any clarification or further help let me know. Cheers. George.