BJM

iTrader: (1)

I have always found it tiring having such tall over-drive gears. This transmission would be much nicer to drive if the gears were more evenly spaced. With 4.10 gears I keep driving 1,2, then 5. In normal driving, 3 and 4 are too close together.

Maybe someone will come up with different gears.

chuckyt1

iTrader: (33)

M12 has different ratios, don't remember what they are though. I have a T56 and 4.10 gears and I like the ratios...

brad8266

iTrader: (23)

I dont like first in the M6.

SladeX

1st gear is awful on the T-56

It's gapped too far from 2nd making awkward shifts compared to the 2-3 and 3-4 timing wise. I like the ratio of 6th and actually wish for something more ie a 0.40 to go with 4.10's.

chuckyt1

iTrader: (33)

Here is a comparison of the T56 and the MN12

https://ls1tech.com/forums/manual-transmission/776536-comparison-f-body-gto-t-56-a.html

transAm-98

iTrader: (1)

After driving a couple of T-5's you'd think that our T56's are the best thing on the street

PewterScreaminMach

iTrader: (7)

MN12 (GTO) trans here with 4.10s. Talk about steep. The 1 and 2 are extremely short, 3 is pretty short, and 5 and 6 on the highway aren't best for gas mileage, but even 5th pulls pretty hard in the car now. I went this way because when I'm at the track dumping the clutch from 5-6K, I want this bitch to scream.

The one issue I like the least is that the space between third and fourth is huge. For street driving, if I drop to third, it can't be any higher than 70mph, and even that is a real quick shift. Anything 50+ I have to go into third. First gear is totally useless on the street in any temperature even with my Nittos.

Basically from a roll, 40 is the sweet spot for second, 60 is the sweet spot for third, and if I have to drop to fourth because I'm too high for third, it's usually a bit low for fourth because I don't start roll racing at 90mph. Again, first is useless; I don't even know how slow I have to be going to drop to first because there's no point.

BJM

iTrader: (1)

If anyone is using 5th gear for real power then you would really benefit from correcting the gear spacing. BMW 6 speeds use the same geometric progression we do in gears 1-4 (ie. each gear drops the revs less than the last one) but they do it from 1-6, makes for a nice street driving car.

melchoir

iTrader: (4)

I'm installing an M12 with my 3.23s. Should be a decent combo.
Pretty similar to a MN6 with 3.73s for 1-2-3, and I think it's better for 6th on the highway.

4.10s would be far too short with that tranny gearing unless you're solely drag racing IMO.
Probably really fun WOT from a dig, and too short for the popular roll speeds like you said.