A C&T is easy, problem is tie rod to radius arm only allows for about 3-4* iirc.
Ya can't just move the tie rod to the front of the axle making it crossover steering like some have said in this thread. Completely re-work the panhard and yes that will work. Not easy to re-work the panhard with coil springs, they are in the way. At this point it is like, really? Should I do all this work to keep the radius arms and 8" HP axle?
Honestly, no you shouldn't. Better to just build a custom axle, imho.
I converted my 80 to crossover and did a C&T on it. It worked well except under max compression, then there was major issues. Dangerous issues. When I sold that (I put that 80-chassis under an FJ62), I told the guy to remove and change the front axle and steering because it was dangerous and I am not responsible for what happens it you do not.
Now if you are willing to cut and weld, axle side of things + frame side, you can set it all up super sweet with the stock radius arms and whatever lift you want. People don't really seem willing to do this, not many anyways. But really, if you want it all, IE lift over 3", caster perfect, pinion angle perfect and coils that are not bowed in their buckets....cut it all off and start from scratch is my opinion. If you want all that and flex, go 3-link. If you want all that and lot's of strength, go custom axle. Otherwise, imho it is just band-aids.
On my current project, I am converting a 1990 70-series to coil sprung front suspension using Toyota parts to make it just like a stock 1999+ 70-series that is coil sprung from Toyota. I really wanted to keep it crossover steering but it just was not possible with the factory panhard. To re-work the panhard is a huge can of worms and it may not even be possible with coils because the coil spring and bucket is in the way, that is if you want to keep the panhard as long as possible as you should. So what I did was cut off the 70-series HP axle's knuckle balls. I then cut 80's off a donor housing as well. I have put the 80's knuckle balls on the 70 housing to convert the steering to 80-series style. More work than I had planned but in the end a stronger axle since I am now using the big 80 birfields. I also had to use Delta radius arms but that had nothing to do with caster or anything else. I needed a radius arm 1.5" shorter than an 80's because on the SWB truck I am doing the conversion in the trans crossmember is in the way. I opted for Delta arms over building a new crossmember from scratch.
I set pinion angle at 2* and caster at 4.5* on this axle.
Any ways, my point simply is, you can get it perfect but not without cutting and welding. The Delta arms are an awesome product and solution but they only fix caster. When I did my 80, the objective was to make it stock specs (or better) with 4-6" of lift. Had I just went a bit father with cutting and welding I think I would have had much better results. And don't get me wrong, I did have good results but again, it was dangerous under compression because panhard and steering started touching.
Cheers