K-Member / Rack & Pinion Steering Suggestions
Wait, so, you said before you "don't think they are really doing anything of significance". Which makes sense considering you don't offer any way to reinforce that area. Now you're implying that the added stress they're going to carry to the "windshield area" is somehow going to be a problem?
C'mon man.
The "windshield area" is supported and made up from the A-pillars, which are one of the strongest points on the car. They do a lot more than just hold the windshield, they're one of the major structural components of the chassis. And tying J bars or inner fender supports into the cowl and firewall and therefore into the structures that support the A-pillars doesn't just add stress, it disperses load. The chassis reinforcement doesn't have a one way switch, they may share some load from the forward part of the frame rails and chassis but they will also disperse load from that area forward as well. Chassis reinforcement spreads the load over more area, which reduces the impact on any single component. That's true always, but it's especially important on a unibody.
And again, it's not just a matter of "liking them". I've driven my Duster with and without them and I can tell you that they make a tangible difference. Especially with 1.12" torsion bars and 275/35/18's up front and 295/40/18's out back. Are they necessary for a street cruiser? Probably not. But that's not nearly the same as saying they're not significant.
There's absolutely no way I'd run any coil over conversion without additional chassis reinforcement to compensate for the change in how the chassis is loaded. That's my bottom line. You can't say the coil over suspension doesn't load the chassis differently, clearly it does. It's just a fact of how the different suspension designs disperse load into the chassis.
It doesn't solve the problem of 50 years of corrosion on the unibody chassis, it just ties a unibody chassis with 50 years of corrosion to a frame. That frame doesn't work independently of the body you attach it to, it has to work with it.
It comes back to "what does it get you". C6 suspension. Maybe IRS if you spring for the big bucks, otherwise a 3 or 4 link you can add without a full chassis replacement.
The Red Brick was able to hang with a C6 vette, just torsion bars and leaf springs. The Art Morrison chassis sure is a fancy gig, but it's just another way people that don't know anything about suspension or chassis spend a lot of money so they don't have to learn anything about suspension or chassis. They do not provide some unobtainable level of performance, they just make it easy to write a big check to a shop to build you a fancy show car.
You stated " The Red Brick was able to hang with a C6 vette, just torsion bars and leaf springs."
I think you are oversimplifying how the Red Brick can stay with a Vette.
" Here's the builder's description of "The Red Brick"
1968 Plymouth Valiant 427 Engine Swap - Mopar Muscle Magazine
Mostly original paint (doors and Dr fender repainted, don't quite match), all steel body, torque boxes, frame connectors, 6 pt (non intrusive) cage, firewall to frame rail bars underhood, XV front chassis (radiator) brace.
Engine, 7.0 liter Small Block dynoed at 519 hp @ 5800, 506 lb/ft @ 4100: 340 resto block, AN connections at oil filter. HV pump, remote filter, 3 QT Accusump mounted behind passenger seat. K1 4.125” stroke crank, K1 rods, JE pistons 10.5 compression. Edelbrock Aluminum heads - Stage 3 ported by Hughes Engines with 2.08 intake valves. Comp roller cam 236/236 at .050 with .545”/.537” lift, Comp solid roller lifters, Comp 1.5 ratio rockers, Milodon road race oil pan, MSD E-Curve distributor. Edelbrock Victor 340 intake ported by Shady Dell, BLP 650 CFM carb. TTI ceramic coated headers, TTI 2.5” X-pipe
exhaust with Magnaflow
mufflers.
Trans: A-833 with 2.66 first gear in Passon Performance aluminum case. Hurst shifter solid mount. Steel flywheel - McLeod clutch
Rear: 66-7 B-Body housing with 2.94 center section, Dr. Diff clutch type differential. Aluminum driveshaft.
Brakes: Front - Baer 6 piston, 13” two piece rotors Rear—Mustang Cobra rear disc kit from Dr. Diff. Mopar aluminum master cylinder 15/16” piston dia. Wilwood rear pressure valve - adjustable from drivers seat. Carbotech track pads all around as well as street pads for cruising.
Suspension: Front - 1.20 T-bars, 72 K frame seam welded, reinforced with FFI kit, notched for oil pan clearance, boxed for NASCAR-style Speedway Engineering
sway bar, FMJ spindles, FFI upper A-arms, Lower arms boxed with AR Eng plates and setup for heim style endlink. Poly lower control arm pivots w/AR Eng retaining plates, FFI C-body tubular tie rods, FFI Stage 3 steering box with PS cooler mounted behind grille. Poly strut rod bushings. Bilstein shocks. Rear- AR Eng front hangers, F-body rear shackles, 340 rear springs with poly on both ends. Adjustable frame mounted rear sway bar .875”. Bilstein shocks. Has new 275/40/17 Falken Azenis 200 tread wear tires on 17x9 Konig wheels on all 4 corners.
Misc: trunk mounted battery, light weight Toyota 60A alternator, custom dash insert with Autometer gauges, Extra-large warning lights for oil press, H2O and volts. Aluminum
radiator with SPAL sucker fan – Manual switch and thermostatically controlled. Corbeau seats with 4 pt harnesses. Heater/defrost removed, factory glass all intact, wipers & turn signals function as factory.
It takes a little more than torsion bars and leaf springs. This is a highly modified A-Body. Very very well done by someone who obviously knows suspension systems power trains and race cars.. I would guess its out of the skill realm of 90% of the members of this site. For us who don't and still want a great handling car, the kits offered by HDK and RMS come with the engineering done that performs exceptionally well and a relatively simple install.
I am in no way knocking your knowledge or expertise. I'm sure your car handles very well too.