Now I understand.  My personal opinion is there is little harshness removed with rubber bushings. There is a boat load of compliance that comes from using rubber bushings. So I dont use them. Urethane bushings are better but squeak real bad and wear quickly if not lubricated regularly. In my opinion  if you want to find a rubber bushing by its durrometer you will have to hunt and peck till you find what you like. Rubber bushings are usually for stock applications and therefore no one will have them described by there durrometer.. That will make your task far more difficult but not impossible.

Rubber bushings are not all bad. Its the durometer of the bushings that make the difference. What most people dont know is that pretty much all rubber is equally soft. The difference is how much rubber they cram into your pivot bushings. Basically they will cram a 6" in dia rubber bushing tube into a 1.5" diameter sleeve with a press and a steel funnel. Thats how they adjust the durometer for different applications.  The higher durometer required, the more rubber they cram into the bushing sleeve. If you get the oppertunity, cut open a new or lighty used rubber spring eye bushing. You will be shocked just how much rubber they can get in there. Old ones will not expand as much due to a collapsed structure at the molectular level.  A typical 2" bushing will yield a 4" rubber bushing un compressed.

The only reason most American cars of the 60's didnt come with an IRS is because live axles are cheap and can be made to hook up better. Drag racing has always been more popular than all other kinds of racing because it doesnt require driver skill until you advance well above stock vehicles. If you can stomp on a throttle, you can drag race. As for rubber, I agree and disagree. The rubber makes the suspension too compliant. In the front it allows the tires to go out of alignment in corners. At the rear it allows the vehicle chassis to shift off center causing excessive body roll. This is all for the quality of ride by nullifying harshness. The effect rubber has on the handling of most vehicles could be summed up as handling like a row boat in heavy sea's. Todays vehicles have a more harsh of a ride because its safer than a row boat like an old caddy. Being able to drive around a problem is safer that being big enough to survive the impact. You cannot put antilock brakes on a suspension that is too compliant. It just creates problems that the brakes cannot overcome. The Jag rear was designed to be entirely solid mounted. If you look at how Jag took a good Dana built and shipped design and turned it to mush by mounting the carriage in rubber. Speaks for its self. Jag compromised handling for the elimination of ride harshness.The early mopars used torsion springs. The only way these can work is by placing them at the pivot point. This puts them at a mechanical disadvantage. A coil spring properly placed as close to the wheel as possible will support the same weight at 1/50 th the spring weight and size. The early geometry is archaic. The caster/camber curves were based on bias ply tires and will not perform optimally with modern radials. Wide radial tires do not require the camber gain that the old bias ply tires did. You cannot expect good results by just slapping modern tires on to an ancient suspension with its bias ply geometry. Entirely new camber curves are requi

The 400 is a rendition of the B block with a bigger bore than the 383. Those 400 make fantastic foundations for strokers. Smaller than the 440 with the potential to be bigger than the 440 internally. All I was getting at was the springs can be removed with the spring eye hanger leaving this reinforced pad for building a new custom bracket for supporting the leading link as well as the triangulated lower differential support mount. That is how the K/A was set up but on the mustang you run into trouble getting the diff support hitting the frame rail preventing it from fitting into the front spring eye mount. A custom bracket must be made to attach the diff support to. I extended the bolt through the frame so the diff mound could be held at the correct location sandwiching the frame. This was no easy task because the rocker is in the way of a long enough bolt to fit in.  You will not have this problem. I am aware that your platform has other short comings but they are sum what minor. That said. It sounds like a fun project !
 

I have the entire set up still. It would be easy to get those lengths for you. Its 1 am so it will have to wait until tomorrow. The upper mount on the bearing carrier has 1/2 inch holes on 1 inch centers. All of my links used heim joints so they all had one inch of adjustment on each end.The trailing link had to be replaced due to length issues but I saved the two original links. They are all stainless and looked pretty sharp. I made threaded ends and welded them in at work where I could use their stainless wire. Then I turned them full length so all of my work was invisible. I agree with your assessment of the design in theory but the actual way the first iteration performed I couldnt really feel the dramatic  anti squat I was expecting. However it did deliver far better grip than the jag xj6 ever did with out wheel hop. In all fairness I beat that K/A set up pretty damn hard. I also used two adjustable coil overs per side. The engine could overwhelm the tires so easily in my opinion the anti squat would have been more pronounced with better tires and alot more traction. As I recal the original K/A design used non adjustable leading and trailing links. The inner mount of the LCA was all the adjustment that design had. For exact numbers I will have to find my original drawings with all the pivot points layed out at 1/2 size. What platform are you putting this under?

The five link has a favorable toe charistic built in plus it has anti squat in its geometry. I wish I had the link but there is a aftermarket 5 link being sold and the engineer that designed the kit explained all the benefits and the guy knew his "I used a word I shouldn't have". As for my car... It doesnt launch like it did with the 9". However it doesnt do too poorly all things considered. The Tires I am running are not drag slicks, there low profile P zeros and are fairly soft. I cannot get any where near full throttle in first or second but it will launch as well as most 16 mustangs and camaros. More importantly it will do circles around them cornering.  I have a Fontana aluminum block 351 Cleveland with a 4.125 bore and a 4.000 stroke. That comes out to aprox 427. The same as a LS7. bore and stroke wise only I built it 10 years before the ls7 . I have the C3 roush nascar heads and valve trane. They were cheap at 2K on Ebay.  The crank is steel, the rods are H beam eagles and they are attached to forged JE pistons with floating pins. It has a hybrid dry/wet sump. CONFUSED? The Grigs racing front suspension would not clear the front sump of the pan with the 10 inch engine set back. This puts all of the engine except h2o pump behind with the front axle center line and provides a near 50/50 weight split. Sooo I have a dry sump pump and a rear sump pan with a roving pick up and no front hump, lump or anything that would interfere with the cross member related to the oil pan. I have a 50mm roller bearing type roller cam from cam dynamics.I had no choice, thats what the block was bored for. and a stock type would not work no way no how. It has 645 lift on E and I on 108 lobe centers. Its a little nasty sounding and performs very well. The Dana 44 in the jag rear has its work cut out for it.

Putting the lower control arm at the angle the xj6 uses works fine with a low hp/weight ratio. Add  more than twice the hp and reduce the weight by 1000 lbs and you will have wheel hop. I did not eliminate anti squat entirely. I reduced the angle from aprox 3 deg to about 1 degree. Anti squat/ lift under braking really is not that huge of a concern on a car that has excelent shocks and is balanced(sorted out). Those charistics are from the relm of crappy shocks and loosey goosey rubber mounted suspensions running bias ply tires. The kind of car that you can wag its tail by turning the steering wheel back and forth at speed. I am a machinist and the steel was free at work from the rem bin in the saw shed. While I was converting back to the Jag set up I went to larger vented 12 inch rear rotors and used helsey hays 4 piston calipers that came off the frount. This was the secondary reason for making new inner mounts. The pivot had to move down to clear the rotor. . I also made half shafts from 1 ton Chevy truck drive shafts getting rid of the heavier solid Jag units. Tube drive shafts are easier to cut to length than the old solid ones were. The set up is narrowed from the jag width. When I shortened the solid jag axles they kept cracking so they had to go. When ever you weld a torsion loaded solid shaft, cracks are inevitable. The solid Jag rear brakes were insufficient for stopping once I made 6 piston calipers and 14 inch rotors off an Escalade for the front. I had to increase the swept area as well as the distance from center at the rear to get the brake balance back up with the front. Confusing I know. Years ago when I was running a 9" rear I used under ride traction links that attached to 6 inch long lever arms welded to the bottom of the axel tubes. The other end attached to the front spring eye mount bolts. The resulting angle produced nearly 90% anti squat. The car hooked up great but the unsprung weight sucked. My 67 shelby is set up for road racing not drag

The XJ6 has too much antisquat for anything more than about 250 hp in a 3500 lb vehicle. The lower control angle is is too steep. Under acceleration the rear wheel load path would literally lift the rear of the car until traction was broken then the rear would fall back down only to gain traction and start the cycle all over again. I have enough torque to make the rear tires leave the ground under hard acceleration. This was very violent and sounded like it was going to come apart. That was why I put together the modified KA set up. Eventually I resolved this problem by reducing the anti squat to nearly zero like the XKE. Then I revalved my rear shocks and have been running 335 / 35 / 19's with out any problems since. As for the link locations, I studied the KA design as he built it and discovered toe charistics I didnt care for. Equilizing the distance the leading and trailing links were from the axle centerline combined with seperating the wish bone lower control arm into two parrallel links eliminated nearly all of the toe in/out that comes with that design. When the suspension goes through its travel the leading and trailing links being equdistanl from the axel made the center of rotation on the axel centerline. With the lower control arms seperated there is no fore and aft movement of the centerline when viewed from above. This eliminates the change in toe to less than one degree depending on static camber setting. Again. My real goal was to get rid of wheel hop and it did. I also have an engine that makes over 550 ft/lb's of torque. This overwhelms the 9 inch wide tires I have now. You can guess what it did to the 7 inch wide tires I used with the afore mentioned suspension.

Thats a Subaru diff. It will most likely have 3.90:1 ratio due to the fact that 99.9% of them came with the 3.9 ratio in the transaxle. The pinion is the counter shaft so changing ratio is all but impossible with out factory support. The simbol next to the 12 on the rear cover is the simbol for the Subaru casting facility. That pretty much nails it.

I thought the older MB cars pivoted near the center making them like a swing axle. Kind of like an old v dub.

Its definitely a Jag rear. To verify the year with out id tags you will need to pull one of the inner stub axles to see if it is supported be ball or roller bearings. Early Jag rears used ball bearings and are not desirable. To find the break down of years you need to look in the pages of the old forum.   There should be washers with O ring seals behind the nuts in your Pictures. The lower control arms should be supported by needle bearings at the inner pivot and tapered roller bearings at the outer Pivot. Bushings in either location will not be stock jag parts. Bushings will not last as long as needle bearings but some people like them. I prefer bearings.

Mine is an 08 TRD 4x4 with an electric locking diff. Like you I couldnt be happier with it. Its one of the best trucks I have ever owned. Its my second Tacoma. My first was a 97 4x4 with an electric locking diff. I got it wrecked with 65000 mi at an auction for $800, It was rear ended hard enough the rear bumper almost held the rear tires off the ground. I shortened the frame and put a 48 Volvo 444 body on it with a Buick GN turbo had a buddie re flash the OBDII computer, a mack truck intercooler the same size as the radiator. I set the boost at 14 PSIG and the thing is a sleeper from hell. I still have it but dont drive it much any more. I am assuming the KB pistons you are planning on buying are Hypereutectic. I am not a huge fan of them but if you stay away from boost and N2O you will be happy with them.They dont expand from heat the way cast or forged pistons do so they require a tighter piston to cylinder wall clearance. This promotes better ring seal through less piston rock and they never make any noise. Hot or cold they are silent runners and a lot of people like that about them. Most KB pistons have an anti friction coating on the skirts. If you can.. get this feature. It is well worth the money.

Its amazing what can be done with an extra .300 inch of deck height. You are on the right path with the long rod kit. The stroker kit wasn't a waste of money, I got the hp gain I wanted and a mountain of torque that came along for the ride. I just like engines that can wind up into the twilight zone. In all reality, the long rod engine will put less side load on the cylinder walls while creating more dwell time at TDC and BDC. This equates to more power through less friction and less spark advance provided you have efficient cylinder heads. Too much spark advance creates negative work, a power parasite. The biggest down side to extreme strokers in how the piston skirts get pulled out of the bores at BDC. This allows the piston to rock on re entry. A bad thing... The heads I got were set up for Ti valves with 5/16 stems plus the Ti units were cheaper used than new stainless. I figured what the hell. I have rebuilt lots of rods over the years and because of this I personally like H beam units with cap screws and floating wrist pins. They dont use the bolts to locate the caps and floating pins reduce friction. I have seen too many caps shift on final assembly causing crooked bearing wear. This was the cause of a rod failure on one build I did many years ago. It was a twin turbo SBC so who cares, right...all in good humor.

Nothing wrong with doing your home work before spending your hard earned money. I have a 67 Shelby with a 408 cleveland. C3 heads and an old aluminum block, steel crank,H beam rods,Probe forged dished pistons, Jesel valvetrain, Ti valves and retainers. All thanks to E bay. I want to go to EFI so bad I cant stand it. Just cannot afford the set up I want that will allow me to put twin turbos on it. I have the turbo's and fabbed up the headers with waste gate outlets out of stainless. I copied a Griggs racing GR350 front suspension and put a jag IRS in back. 19 inch wheels, 3.50 gears with posi. 14 inch rotors w 6 piston calipers in front and modified rear inboard brakes in back that are fed cool air from the stock scoops on the GT 350.  It isnt slow right now, I just seem to want stupid fast. Too much U tube I guess. I envy your ability to use a ford FI set up. Thats way cool !!!

Great software to get your lay out pretty dam close before you cut into anything you had to spend money on. Isnt technology great these days? We use auto cad at work for all of our Haas machines and it is very similar to your computer aided drafting software. Beats the hell out of the trial by error or poke and hope with a welder. The weight bias you are shooting for and the power train you chose should make one hell of a ballistic rabbit. Please post pictures when you have something assembled far enough to be proud of.