Calling all corner carvers!
Thank you very much, so much good information. Question, What are FMJ spindles?
I agree with you about the T56 transmission, but I have reason's to stick with the stock 4spd. Basically, the car was my fathers since 1970. I have it now and I just cannot cut the car up. I was going to mini-tub the car as well but decided against that. I just don't want to do anything too irreversible to the car. I will never sell it, but there's a small chance it could be restored back to original one day maybe when my son owns it. Also, I just don't want to run a stroker in this car. I love the idea that this Swinger 340 was orginally a high revving small block car back in the day so i'd like to keep that theme but take it to another level. Otherwise, my other option is to build a budget Magnum 5.9L and bolt on the BW 75mm turbo I have on the shelf. I still am leaning towards the 340 build though.
I think I will run the 3.55 for most of the time. I will then get another 3rd member with a taller gear set once I see how the car is with the 3.55.
Thank you again for all the great info. Looks like I will be ordering just about everything you recommended LOL.
The "FMJ" spindles are the 73+ disk spindles used on the later F, M, and J body cars. They're the slightly taller ones that Rick Ehrenberg pitched a fit over in his "disk-o-tech" article. Of course, he never actually bothered to check the geometry, he just made assumptions. Turns out the taller spindles don't change the geometry all that much, and for cars that run wide front tires most of the changes are beneficial. I run FMJ spindles on my cars. I don't know for certain as I haven't measured them, but since all the reproduction 73+ spindles are marketed to all the different body styles I assume they're actually the taller version that came on everything else (B/E/F/M/J/R). A-bodies were the only ones that got shorter ones, and it's really a small difference. Honestly I wouldn't worry about running either one, the difference is very small and not worth seeking out in my opinion. I have the FMJ's because the later cars like Diplomat's still showed up in the wrecking yards around here when I first got all my cars. Anyway, the
real info on the changes is here
Swapping Disc-Brake Spindles - Mopar Muscle Magazine - Hot Rod
I understand not cutting stuff up too much, especially something that has sentimental value to you. The easy solution to that is to use an 8 3/4 and just have a few extra 3rd members. Or at least one, you could have your usual street gears and then a sub 3.xx set for long tracks or long trips. A set of 2.94's would be pretty great. Just be careful with your cam selection. The 340 in my Duster is a 9.8:1 compression, ported head deal with a Lunati 70404, and that particular combination calls for a 3.91 or better rear gear and it means it. I ran it on the street with 3.55's, and it was pretty noticeable starting from a stop and a bit of a pain in the *** in traffic, it definitely took some clutch work which isn't ideal. But that was about the best I could do and still manage 70+ mph freeway speeds at a decent rpm with 26" tires. My engine likes the 4.30's way better :D. But that depends a lot on use too, if it were just a fun "weekend car" I could run 3.73s or 3.91's and not worry about the freeway cruise as much. And I wouldn't be stuck in traffic as much either. But as my daily that issue was definitely more noticeable.
Ok, looks like I'll be going with the following so far: Firm Feel 1.12 torsion bars, Hotchkis UCA's, QA1 strut rods, BAC delrin TB bushings and greasable pivots, QA1 LCA's, Hellwig "pro touring" sway bars, and Hotchkis/Fox shocks. I still need to figure out the best steering solution and what stock height spindles to use. At least I can order my rear shocks to finish the back of the car.
The QA1 LCA's you get will likely not be the older version at this point, so you may want to modify the bump stops. The differences are shown and discussed in this thread, easier to link it than pull all the pictures over.
QA1 Lowers Create Bump Clearance?
They will also come with rubber LCA bushings installed, so you will need to remove those and the shells to install the Delrin bushings. My install is here-
My "new" '74 Duster- or why I need a project like a hole in the head
Like I said above, I wouldn't worry about the spindles. Just buy a 73+ set from DoctorDiff. They will likely be the taller version, but the difference is so small I really doubt most people would notice on the street, myself included.
For steering, if I was starting from scratch I think I would use the Borgeson power steering set up.
@BergmanAutoCraft sells the whole kit with everything you need, haven't seen him chime in here yet so he's tagged now. I run a FlamingRiver 16:1 manual steering box. Don't get me wrong, I like it. But with 275/35/18's up front with +6.5° of caster it's not exactly user friendly below 10-15 mph. Above that it's magic, below that it keeps my forearms in shape. The Borgeson is a 14:1, so it will be quick without being an arm burner in the parking lots. With your 3" inboard springs, even without the mini-tubs, you should be able to run 275/35/18's all the way around if you're so inclined. And that will make the Borgeson a nice deal up front.
