Ok all. I have searched and found a bunch of pics and info. My quandary is really a strength and clearance question. Is there a significant strength difference between the 78/79 F250 4x4 power steering gear vs. the saginaw 2 wheel drive steering gear? I am going to be using either one for a cross over steering / Cummins conversion with my 78 dana 60 front. This is all eventually going into my 74 F250 4X4.
<OThe saginaw <ST1</ST1box requires you to mount it on the outside of the frame. When used for crossover steering, there is a clearance issue between the drag link and the cross member. With the 78/79 box there doesn’t seem to be a clearance issue. However with a P pumped 94-97.5 Cummins you have a possible clearance issue with the vacuum pump/power steering pump and possibly the intercooler piping. If anyone has installed or seen a highboy with a P pump Cummins and a 78/79 box, I would appreciate any input on any clearance issues. In my head I don’t see any clearance issues but my head has been wrong before.
I am to the point in my Cummins swap that I am going to have to mess with, and buy the steering box etc. My F150 steering gear is going to have to go. It interferes with the intercooler piping and the cross member with cross over. At this point I am going to be fabbing a removable cross member anyway. I would prefer to run the 78/79 box vs. the saginaw. I prefer the 78/79 box simply because it is inside the frame and away from the tires. However if the 78/79 box interferes with the Cummins, or is less strong than the saginaw box I wont. Thank you for any input anyone has. <O
I'm using 78-79 box on a VE engine. I forgot to set the steering pump on when I had the engine in last week but I nothing jumped out at me as far as it not fitting. Oh boy!
I've been through HRDRKN's thread time and time again and I
never read where he had any issues with the box although he did fab his own CM. I want to say he used aftermarket intercooler also. Possibility?
I remember your going to fab your own CM. How about moving it back giving clearance for the crossover setup. I"'m sticking with the 2wd CM and it looks pretty good for the CO setup.
Would it be too much trouble to reroute the intercooler piping? I haven't got that far yet.Wish I could help more.
Yeah. I really don't think the intercooler will interfere. The piping should be outside if the radiator but still inside the frame. I am mostly concerned with the power steering pump interfering with the 78/79 gear box.
I'm deffinately fabbing my own crossmember. I think it will be less work then modifying the factory 4wd cross member. Plus Im going to make it bolt in.
I'm probably going to trim and box my CM to give the axle some additional space and also to "hopefully" give some clearance for the tie rod.
If my axle moves backwards at all during it's cycle then the highest part of the axle should go right in between the lower edges of the crossmember in stock form. I need like a half inch and I gain a bunch. I've mocked up the crossover and tie rod and had a few discussions with NW fab about the setup in this truck so they gave me a few ideas as far as what I would need for clearance during compression of the leafs.
Worst comes to worse there is always bump stops.
I'll be putting the engine in again Tues/ Wed and I'll let you know if I have issues with the box.
HRDRKN tried to get a nonstock pump to work in place of the stocker. I think that was due to the hydro assist he was attempting to use. Haha...I have his box.
Part of my thinking with the saginaw swap was parts/replacement availability if I were to break in mexico or somewhere else out in the boonies. The saginaw boxes were on all sorts of stuff & are easier to find. That may or may not be part of your decision making.
Also the saginaw box has a shorter sector shaft. Shorter shaft = less leverage on it/the box = less likely to break (in theory). Again I build stuff overkill and the 78/79 box will probably last fine without breaking depending on tire size and usage.
As for clearance with the 78/79 - can't help you there. I will say it SHOULD clear the IC piping from what I can tell. Then again that also depends on what IC you use.
Parts availability wasn't in my equation, but it should be. I do like the way the 78/79 box fits better. But getting a replacement sure isn't as common though.
Based on your pics it looks like the 4x4 cross member is quite a ways further forward too. I'm hoping that it fits a bit better for cross over steering purposes. Either way my cross members getting removed anyway.