Convince me to put a TKX in my Dart
My current engine is a bit on the milder side, stock 5.9L Magnum short block with ported Edelbrock heads (9:1 compression), port-matched RPM intake, 750cfm Street Demon carb (later going to a 750 Holley DP-style), custom-grind hyd roller cam from Racer Brown with 222* @ .050" intake duration (IIRC). I put it together with Cometic MLS head gaskets and ARP head studs so it's ready for boost but as it is it puts down 290 *uncorrected* HP at the rear wheels at 5000' elevation. Has a reasonably lumpy idle but pretty much smooths out by 1500 RPM. I think the biggest "cork" in the system is the Hedman shorty headers going into 2 1/4" head pipes, I have a set of Doug's D-453 long tubes waiting to go on the car and they'll get 3" pipes off the collectors then neck down to 2 1/2" to mate to my current mufflers and tailpipes. I currently shift it around 5500 RPM but with better headers and exhaust I think it would pull past 6000. Also need to upgrade to roller rockers and B3 geometry kit I'm sure that'll free up even more top-end power and RPM.
With that said the car is more of a weekend warrior at this point. It has about "half interior", carpet and seats but no headliner or door panels. Over the past few years I've built up the suspension for autocross and road racing stuff, between that and the lack of sound deadening it's kind of tiring to drive at freeway speeds for more than a couple hours (wind noise!!!!!) so I'm not looking to make any long road trips with the car although it's not outside the realm of possibility. I know the T-56 is like the holy grail of 6-speeds but I don't see my car having much over 600 lb-ft even after adding a centrifugal blower and the engine makes decent low-end torque so it doesn't really need short gearing. Up until now it's had 2.94 rear gears with a 904 auto and cheap loose 2600-RPM stall converter and while a bit sluggish off the line it's not too much for the engine to climb out of.
Right now I'm in the process of putting 3.55 gears in the 8 3/4" and would probably retain those after a MT swap. Not entirely sure which gear set I'd want in the TKX but leaning toward the "wide-ratio" one with the 3.27 first gear and 0.72 overdrive which with my 27" tall rear tires would put my 75 MPH cruising RPM at just under 2400. I got used to cruising at 3000 RPM at that speed for years so that's quite a drop to me. 0.68 5th gear would bump cruising RPM down to 2250, 0.63 6th gear in a T-56 would be just over 2000 RPM. I understand that would be nice for a long road trip but my car isn't really set up or intended for that. I also like the idea of ~40lb less weight near the front of the car and an overall smaller package to deal with compared to a T-56.
Still a ways off until I have the kind of money needed but that's my thought process.