TKX vs T56

cli55er · 2025-12-27T14:23:13-0600

DionR said:
I struggled with which way to go, too. I liked the lower cost and smaller size of the TKX, and I found people beating the snot out of them without issues (outside of the one above). But the OD ratios always ended up on the shorter side to me, more so since I was planning a G3 swap with EFI and knew those could cruise at 65 mph at 1500 rpm with ease.

In the end I went with a T56 Magnum from SST. I was pretty sure I was going to regret a TKX, not because it is a bad choice but because I would always wonder if a T56 would have been better. So I just bought the one I knew I wanted.

Yeah I would be the outlier…. Or those people didn’t have near as much HP/trq. I cruise at 70mph at 2200rpm. 3.73 rear.

1WildRT · 2025-12-27T15:59:13-0600

FWIW My combo is a 70 340, 10.2 C/R 230@ .050 Edelbrock heads... Probably 325ish HP flat torque curve from 1700-5000, spins happily to 6500...
3.55 gear, 3.27 1st .68 5th.... 28" tire.... 2000rpm in 5th = 70 MPH...

Max65 · 2025-12-27T16:06:36-0600

DentalDart said:
Care to shed some light on why someone would choose 1 over the other?

Is one more comfortable to drive? Or more fun to drive?

If you start explaining gear ratio numbers I will not know or understand anything you’re saying so say it is stupid people terms like you have to shift out of first fast, your car loses power when shifting into last gear.

Photo for fun… 70 degrees and sunny in SW Missouri for Christmas.

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Max65 · 2025-12-27T16:25:50-0600

I have a Chevrolet T56 in my 65 Barracuda. I put in a T5 before that and it had a factory A833 4 speed originally. 5th gear is fun from 60mph to 90mph and 6th gear is fun after that. 80mph is about 2000 rpm in 6th gear. The T5 shifts REALLY smooth, the T56 is a little more notchy but not much. Motor is 475 lb ft torque so I went to T56, that extra gear is great and easily keeps up with modern cars at hwy speeds and helps a lot with fuel mpg