I put this together to try to help understand rear gears in relation to manual transmissions.

I've got a 3.23 rear with an M20 so the final drive ratio is 8.13. It's OK for normal driving but it doesn't launch that well. My next large investment will be the Autogear Muncie. Some 3.08 gears to go with that would be ideal for 1st gear final drive ratio and better highway cruising. This table also shows why you need a radical rear end gear to go with the M21 or M22

I suggest you strive for a 10-ish first gear final drive ratio. Mine is 9.09. My first gear is 2.56 x 3.55 rear = 9.088. I run an OEM height tire: 26.4", 225/70R14 (F70x14). A shorter or taller tire will effect the ratio. My plan is to switch to a 4.11 (x 2.56) giving me a 10.52 final drive. IMO the ratio you want is highly dependent on your traction or desire for it. I have no desire for it. I just like to smoke 'em. If you have taller and/or sticky tires you'll want a 10+ ratio. If you run OEM size or shorter tires a 9 ratio is just fine. I'm assuming you also have a Safe-T-Track rear or equivalent. Why worry about this with an open diff? Also consider the MPH you drive. I rarely drive on roads with 50+ speed limits. Since I drive 45 or less a 4.11 rear will be no big deal. An Autogear transmission can be built in any configuration. I don't recommend a 2.98 first gear. While this may help with launches, you'll end up with a really W I D E ratio transmission. That'll suck big time.

I would love to have a 3.55 in my rear differential. I opted for 3.36 and I now I wish for a 3.55. I just can't justify the cost to go from 8.46 to a 8.95 final drive now.

One inch, you don’t think I’ll like the really wide ratio? My thought is you can get the best of both worlds with a 4 speed: 2.93 or 3.08 gears for highway cruising but still a good launch withwith the 2.98 1st gear

I feel your pain Harold. I’ve got 3.23’s

Bob, I like my 3.23s. Sure I'm not the fastest car off the line but then I'm always looking for that extra gear at the end of the freeway off ramp too so it's a pretty good compromise without going in deep for some sort of overdrive in a car that I only put a couple thousand miles a year on. I did spend a couple hundred installing a power trax unit so at least I've got both wheels pushing me.

I was always ok with the 3.23’s as a good compromise but lately I’ve felt the need for a better launch. I roasted the flywheel at the track a couple years ago. No wheelspin on the sticky track.

I have an OEM GM 3:55 ring and Pinion set if you change your mind.

I would love to have them. Just a little rich for my wallet.

The launch is a mystery to me. I've never really been able to crack that nut. Most times I roll out pretty easy like a 2.4/60ft. I tried one time without traction bars on the car. Revved it up to about 4K and dumped the clutch. The car was bouncing around so much I thought I broke something. Pushed in the clutch and then let it out easy. I was relieved to find it was ok. These days I won't even give it too much pedal til the clutch is fully engaged. Even still, without track tires, the tires spin the majority of the way down the line. Can be frustrating for sure. Starts to feel like playing golf. I'll stick with my 3.23s.

Anybody else besides oneinch want to talk me out of the 2.98 1st gear Autogear Muncie? That was the point of me starting this thread - to solicit some opinions from the knowledgeable. My plan, pending funding, is to get the Autogear and use it with my 3.23's to see how that works. Then maybe later think about some 3.08's.

I'm not going to talk you out of it. I have a 2.95 first gear with a 3.08 and love it. For the way I drive it, street only, it is perfect for me. With a .63 overdrive the highway cruising is just where I want it. Sure, you can't use fifth around town at all but that's not what it is for anyway. With a 4 speed highway cruising will still be comfortable.

I'm sure i could google to find out, but what is a AutoGear Muncie?

Autogear is a company that makes new Muncies with all new parts. They offer a gear set with 2.98 1st.

Here's an Auto Gear Super Case Muncie, from Midwest Muncie.

https://www.midwestmuncie.com/product/new-auto-gearsuper-case-muncie-m22-rock-crusher/

Thanks for the info!