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.