76 Toy, make sure everything is new, tight, or in spec (sounds like you have). Do some searches with "death wobble" here and at Pirates. Some good discussion and might bring up something you have missed.
I have flat steer arms (custom OTT flat arms, OTT relay/tie rod/pitman arm) new bushings, new springs, 4 deg + caster, completely new front end components, knuckles set at 12-14lbs, wheel bearings at upper end of spec, tight steering box, new u-joint in the steering shaft, u-bolts tight at the springs, new TRE's, wheels balanced (35x12.5x15 TXR), tried a variety of toe in measurements, and would still get the DW if I hit a bump at a certain speed, with the right angle. I was into the front end countless times replacing, checking, etc.
Put a damper in the stock location (frame to relay rod) and would still get it if I hit the front left tire on a sharp drop (manhole cover with 2" lip or so) and going about 35-40 mph. Brutal. Into the entire front end and steering countless times again, increasing knuckle pre-load, checking other things.
Ended up having a bracket welded to the spring perch, and went from that to the tie rod. Steering wheel hardly moves when I hit a bump now.
Perhaps there is something not quite perfect in mine that causes it. I could not figure it out though, and ran out of time (had a trip coming up).
Don't know if there is enough room at the rearward spring perch to weld on a bracket. Everything is on the front with my set-up, and it worked out great (cept is it in the front where damage is likely).
Ohhh...this is on a BJ60.
And one last edit...I have heard nothing but good about Luke and his product! Will use his stuff on my BJ74 when/if it gets SOA. Talk to him and see if he has any ideas.
Are you running saginaw steering or stock? I am still running stock and I simply flipped the steering stabiliser around towards the front of the truck and it fits fine. I also flipped my springs and went SOA at the same time.
Did you change your tire/wheel combo at the same time you installed the steering? If all your changed is the steering arms then check your toe. If you changed anything else check your caster and everything else mentioned above.
SOA, but was your axle properly cut/turned for the increased pinion angle, caster and tire size? Caster can be a major contributor to ill handling on the road.
I don't run a stabilizer on any of my SOA rigs, but I do run a hydro-assist setup on my FJ40. When I send a customers Cruiser out the door, they don't need a stabilizer, but may have one to appease their needs.
I have Luke's hysteer on my 72 with 38.5 x 15.5 tires. Prior to CM2005 I took it out for a test drive and I got the wobble also. I redrilled my old stabilizer mounting bracket so it mounts on top of the spring plate using the existing u-bolts, it attaches to the passenger side and the stabilizer just clears the top of the pumpkin and attaches to the top of the rear steering arm. It made a world of difference on mine.
Chris.. How bout welding a gussetted tab to the back of the axle, going to the stabilizer on the tierod? Won't hit anything behind the axle..
Besides. You gotta come out and play before you need a steering stabilizer..
I run a stabilizer, I got death wobble, I can't get up to 35mph in low range so it's really not an issue for me right now!