I have 3.5" backspacing wheels, stock 68 drum spindles with a cheby disc upgrade. Can I do this GM TRO with my wheels?
I don't see why not. Yours is probably the more common setup, and at just 3.5" backspacing, those wheels aren't tucked in too tight. How much clearance do you have now between the rim edge and the steering arm?
Why don't we use the 1 ton Ford rod ends?
Probably just because nobody ever found a more compatible off-the-shelf component from Fords. Pre-'80 solid axle 3/4 and 1-ton Fords didn't have the same setup at all. Post-'80 150's and many 250's were kind of wimpy and also not an advantage that I'm aware of.
The GM "1-ton" (actually they're 1/4, 1/2, 3/4 and 1-ton, but the 1-ton just sounded cooler) have the tapered hole which is what made them so appealing for conversions. The downside is that the hole was originally for mounting a steering stabilizer, not a draglink. It was never intended for a draglink from the factory, which is probably why it's not reinforced more and tends to bend at that point when used hard.
It's vertical orientation also allows some "twisting-English" to be imparted into the tie-rod especially when the ends wear in and get looser.
To toot our own horn, this is why we've kind of stayed away from this setup and went with a more "Ford-like" design of our own for the past few years.
We use an even larger diameter rod-end and beefier (than some at least) centerlink setup that makes it easier to put the draglink mount in a stronger section and keep the draglink at the proper angle and closer to the same length as the trackbar.
http://www.wildhorses4x4.com/category/Custom_tie_rods/a
The #2351 is the full replacement setup for your rig including adjustable draglink, or the #2364 would just replace your tie-rod and reuse your draglink.
Can be flipped for TRO without needing to re-ream the tapered hole too.
Not that a longer draglink of a GM conversion can't have advantages, but keeping the same length draglink as stock can be a big advantage as well.
Can someone with 1.5" DOM tube measure how far it is off the front diff cover at full lock? I have a old Detroit E locker that has the electric motor on the front cover and I am worried about it hitting.
That's a pretty big cover if I remember. Best thing to do is to turn your own wheels to the lock, measure your rod diameter and measure what's left over. Then figure out what it would be with 1.5" tubing.
Paul