Power steering box

Has anyone changed the box without removing the header? I really don't want to get into removing parts that are not required to be removed. Car is a 71 Mach 1 with 351C with a TKO 600 hydraulic clutch setup, so no zbar  to deal with.

Hi - I'm thinking of renewing my box also :whistling: -- but I believe ( may be wrong here  :classic_blush:    ) that there are many different types/ratios. So very interested in this topic -- hopefully an ex-spurt will drive by soon 

1sostatic said:

Hi - I'm thinking of renewing my box also :whistling: -- but I believe ( may be wrong here  :classic_blush:    ) that there are many different types/ratios. So very interested in this topic -- hopefully an ex-spurt will drive by soon 

Click to expand...

No "ex-spurt", but yes, there are different ratios. A used PS box will almost certainly need a rebuild which is doable if you have the tools and the mechanical background to do it. There have been several threads on this by different members, Bentwork and myself included. Check the tag ID on your PS box. If it's a V/R, I'd look at rebuilding it first. These are heavy and shipping will be expensive.

A variable ratio SPA-T or V (71-73) or SPA-AD or AF (after 1/2/73). V/R boxes are 16:1 to 13:1 is what you'd be looking for imo. Another maybe better alternative is to buy an upgraded box with 12.7:1 fast ratio.  There are a few companies that offer these. Others can likely suggest the best one. While at it, definitely look at replacing the idler arm bushing or entire idler arm as well as the pitman arm. Other worn parts should be replaced at the same time if it were me. Ask for brand suggestions like Moog or Rare Parts. No cheapo Chinese stuff. 

More later if you need assistance.

Adding to the above post, I forgot to add the 17.5:1 fixed ratio box tags generally used on non Mach 1's 

SPA-S or U or SPA-AD or AF after 1/2/73.

Manual box tags; SMA-R = 22:1 1971, SMA-T =24:1 1972/73 or SMA-AC or AE >1/2/73

Tnfastbk said:

Has anyone changed the box without removing the header? I really don't want to get into removing parts that are not required to be removed. Car is a 71 Mach 1 with 351C with a TKO 600 hydraulic clutch setup, so no zbar  to deal with.

Click to expand...

I have shorty headers and can drop the box out the bottom.



For 1sostatic…

Turns out with my long tube headers the answer is no. It liked about an 1/8th of an inch no matter how you turned it. So ended up loosening the header to get the box out. I took the header completely off after the fact. New box will be here Tuesday.