T-10 close ratio vs wide ratio?

Wonder if a 3.73 rear would be nice with the 2.23 in the amx ???

70amxvegas wrote: Wonder if a 3.73 rear would be nice with the 2.23 in the amx ???

You'll love it around town but it will be a bit buzzy up on the freeway. I had 4.10s and the 2.23 T-10 and it was a blast to drive around town. Contrarily I hated running at a contant 3650 - 3800 RPM whenever attempting to just keep up with traffic on the big roads although if you wanted to pass someone in a hurry it took off like a rocket when mashing the pedal in 4th gear at 65-70 MPH.

Edited by amx39068 - Jul/13/2013 at 2:30pm

OK, I know I am a bit late on this thread...

Just, I am so surprised that we did not get anyone who has done semi-pro racing involved. Either in track or strip.

Close ratio will get you from zero to top end just as quick as a wide ratio, as long as you shift without messing up in each comparison.

The key is matching up engine torque, with the rear end. High low end torque can have 2.87 on up to 3.25 gearing. Medium torque curved engine 3.55 to 3.74, and High top end torque would need 3.90 on up.

The trick is keeping the engine at or near its peak with torque, so matching gears in the transmission is crucial. Once you established your engine rear end combination.

Having a wide ratio tranny would be beneficial to a small block or road race conditions. AMC did a poor choice with properly matching ratios over what GM had done with their units. So, the way it looks there is no best T-10 from AMC, as each has their gearing strong points and low points.

For me I would take the close ratio with a 390/401 engine. Though you would have to keep the rear around 3.55 - 3.90. For those with 3.15 gears the wide ratio would be best.

I selected a 3.25 rear gear for my engine, since I plan on having a fairly good amount of low end torque.
Now the issue is I will be using a TH400 with performance gears and ratios of 2.75, 1.54, and 1. It is still a far cry from the T-10 gearing, but still in the ball park for a good launch with 3.25 or lower numerically rear gearing.

With a standard 1st gear of 1.54 I would need a 3.55 rear gear. Just showing how similar in correlation with 1st gear in comparison with the 1st gear in the T-10.

There is going to be some people who may say prove different, but it is all about how everything works together. Just keep in mind your rear gear starting point with your engine's dynamics, before selecting which particular T-10 works better for you.

The statements through this thread directly or indirectly correlate with my statement, just too many follow the leader without thinking about the basics.


Edited by 304-dude - Jul/15/2013 at 7:41am

Ray, I run the 2.64 T10 with my 3.54 rear and the 15" machine wheels with 255 60 15 T/As. Traction is a real problem. 13.28 @ 107 with real dungty 60 foot times.

I have a 68 AMX 390 (healthy) with a close ratio (2.23) T-10 and 3.73 rearend. 1st gear is much better than the 3.15 in my Green AMX, but 2nd gear seems almost a waste of time, unless you're really deep into the throttle, then it's just more noise/fun. It is tedious on the highway, but then it's not really a cruiser anyway. The Green car is the cruiser with the 3.15/close ratio combo, but 1st gear requires more clutch even in a 3300 lb AMX.