# Gear ratio



## boblegate (2 mo ago)

What diff gear ratio is best for around town and freeway driving in a 67 gto, 400, 4 sped Muncie?


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## NYTrainer (Sep 19, 2012)

Kinda depends on the carrier series you’re using (there are 3 for BOP). For example if you now have 3.08 gears you can only go numerically higher to 3.23. That series carrier uses 2.94 - 3.23:1 gears.


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## 67ventwindow (Mar 3, 2020)

I use the Tremec calculator. They include muncie and toploader trans so I can compare the different cars I have.



https://www.tremec.com/calculadora.php


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## geeteeohguy (Feb 2, 2008)

boblegate said:


> What diff gear ratio is best for around town and freeway driving in a 67 gto, 400, 4 sped Muncie?


In my experience, having driven these cars with every ratio rear end, the best all-around gear ratio for your car would be a 3.23. Good in town, good on the freeway.


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## BLK69JUDGE (Jun 10, 2010)

Close or wide ratio ?
Tire diameter
Camsize???
All or each. Can make a difference in drive ability


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## lust4speed (Jul 5, 2019)

No one answer either. Bias towards freeway driving the 3.23 would win, bias to more in town driving and 3.55 would be a better choice, and the 3.36 might be the best compromise. I ran my 3.36 ratio since new but the increasing speeds on our local freeways (80+ MPH) over the last few years regulated me to the slow lane. I finally gave up and went with a 5-speed so I could get back in the flow of traffic.


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## armyadarkness (Dec 7, 2020)

boblegate said:


> What diff gear ratio is best for around town and freeway driving in a 67 gto, 400, 4 sped Muncie?


Most widely accepted answer is 3.36... but that's strictly from a performance/ efficiency perspective. It's doesnt take "preference" into consideration... so while it's best for your situation, that doesnt necessarily mean youre going to like it.


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## geeteeohguy (Feb 2, 2008)

Having had GTO's with all the gearing, I will say that for a 4 speed car with regular tires, a 3.23 is far superior to a 3.36 on a car that will see highway use. And an M20 with a 3.23 is a great combo. BTDT with more than one car, and Pontiac built them that way. A 3.36 car likes a 65 mph cruise, a 3.23 car likes a 70-75 mph cruise. The 3.55 geared car likes a 55 or 60 mph cruise. Up to the OP what he wants. Having had 3 first gen GTO's with a 3.55 rear gear, I'll say that they were great in the '70's and '80's when the national speed limit was 55. When that got changed back in 1996 or so to 70-75 mph, the 3.55 gear became suckular. 
I pulled the 3.36 out of my '67 and went from 15 mpg at 65 mph to 21+mpg at 75-80 mph with a 2.56 gear. I love being in the fast lane keeping up with traffic sipping fuel.


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## tallrandyb (Jun 12, 2021)

geeteeohguy said:


> Having had GTO's with all the gearing, I will say that for a 4 speed car with regular tires, a 3.23 is far superior to a 3.36 on a car that will see highway use. And an M20 with a 3.23 is a great combo. BTDT with more than one car, and Pontiac built them that way. A 3.36 car likes a 65 mph cruise, a 3.23 car likes a 70-75 mph cruise. The 3.55 geared car likes a 55 or 60 mph cruise. Up to the OP what he wants. Having had 3 first gen GTO's with a 3.55 rear gear, I'll say that they were great in the '70's and '80's when the national speed limit was 55. When that got changed back in 1996 or so to 70-75 mph, the 3.55 gear became suckular.
> I pulled the 3.36 out of my '67 and went from 15 mpg at 65 mph to 21+mpg at 75-80 mph with a 2.56 gear. I love being in the fast lane keeping up with traffic sipping fuel.


I like the 3.23 and M20 combo for highway also; agreed it is hard with higher speed limits and people ignoring those to run more than 3.23's; had 3.55's in the car when I bought it but went to a new posi carrier and bought a set of pulled 3.23 gears (getting hard to find!) and they are quiet and good for rpms on the highway. If I need better stoplight action I jump in my CTS-V or my 94 Formula.


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## geeteeohguy (Feb 2, 2008)

tallrandyb said:


> I like the 3.23 and M20 combo for highway also; agreed it is hard with higher speed limits and people ignoring those to run more than 3.23's; had 3.55's in the car when I bought it but went to a new posi carrier and bought a set of pulled 3.23 gears (getting hard to find!) and they are quiet and good for rpms on the highway. If I need better stoplight action I jump in my CTS-V or my 94 Formula.


I agree 100%. Have had and driven a bunch of these cars and a 3.23 and M20 is the 'sweet spot' for a stick GTO that is used on the street. Best all around gear, hands down. 
With a TH400 auto car, I like the 2.93 the best, followed by a 3.08. I run a 2.56 posi in my TH400 '67 because it was free and too good to pass up at that price. It's okay off the line, but shines on the highway, where the car is driven 80% of the time.


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## Baaad65 (Aug 29, 2019)

But a 3.36 is fun and a 3.55 is super fun in town 😉 but the later would need an overdrive for the highway....Gear Vendor or TKX you're up.


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## armyadarkness (Dec 7, 2020)

Baaad65 said:


> But a 3.36 is fun and a 3.55 is super fun in town 😉


That's really it. Most of us have these cars so that we can have fun at the local cruises and parking lots. Even with 3.36's, my car was no fun around town, and I didnt dare race anyone... and since I travel on the freeway A LOT, and go very far, I was screwed on all fronts.

I tack'd 3200 rpms cruising at 80mph.

Basically 3.23 will suck around town (unless your engine is a beast), and above it will suck on the freeway. If there was a magical right answer, the topic would never come up.

At the end of the day, there are two ways to beat the math:

Highway gears with a ton of horsepower.
Stop light gears with overdrive.
Otherwise, you're in the middle with 3.23. Go below it to travel, and above it for fun.


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## tallrandyb (Jun 12, 2021)

That’s why I have my 94 Formula: tons of horsepower (bored/stroked/solid roller LT1), stoplight gears (4.11), and T56 with 0.50 6th gear.

Agreed to head in the direction of a “full” GTO solution you gotta go 5-speed; I may do a TKX someday (or do like PJ and buy a TKX now then wait 10 years!).


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## armyadarkness (Dec 7, 2020)

Adding the TKX was a game changer for me, but I did swap the cam, too. It wasnt a huge improvement over my previous cam, but it did compliment the TKX better than the TH400.

My issue is that I organize frequent car shows in my area, so there's a ton of local racing and hot rodding... but my family lives 2 hours North, so I also do a ton of 80mph cruising.

Now with the 3.36 and the wide ratio, I have a final 1st gear ratio of 11.00, so I can lift the front wheels around town, and with 5th gear, I can cruise at 80mph/ 2500 rpms.

Without 5th gear, 3.36's were 3200rpms. Not bad occassionally, but I wouldnt do it regularly.


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## tallrandyb (Jun 12, 2021)

Agreed again: with the T56 and 4.11s it’s a 10.9 first gear ratio, so sometimes I just start burnouts in third gear. And then a 2.05 final ratio but tons of torque to push it.


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## armyadarkness (Dec 7, 2020)

tallrandyb said:


> Agreed again: with the T56 and 4.11s it’s a 10.9 first gear ratio, so sometimes I just start burnouts in third gear. And then a 2.05 final ratio but tons of torque to push it.


This is darn near my exact situation. I dont even need first gear, and although I cruise comfortably @ 2500rpms in 5th, I can roll on and tear off, without downshifting.


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## geeteeohguy (Feb 2, 2008)

armyadarkness said:


> That's really it. Most of us have these cars so that we can have fun at the local cruises and parking lots. Even with 3.36's, my car was no fun around town, and I didnt dare race anyone... and since I travel on the freeway A LOT, and go very far, I was screwed on all fronts.
> 
> I tack'd 3200 rpms cruising at 80mph.
> 
> ...


Very well stated. But it depends on what your definition of 'fun' is. My definition 35-40 years ago was huge burn outs and speed shifting. And racing. And then repairing or replacing blown rear ends, engines, u-joints, and scattered trannys with readily sourced, cheap junk yard parts. Rinse and repeat. As I got older, just cruising around in a great looking and running classic was fun. And now, taking my car on a long road trip a few times a year into the Sierras or to the coast or out of state, the 'fun' is motoring along at 80mph at 2450 rpm with the top down and getting thumbs up everywhere. To me, highway 49 up in gold country with the top down on a spring or summer day is having fun in spades. And the engine is barely turning over and no rubber is being burnt.
That said, I DO have 3.36 gears in my other GTO and Corvette, which is about right for the way they are driven. The 'vette has a 389 engine (.030-0ver stroked 327) and the goat has a 394 (030 over 389). Both cars are 4 speeds. Here in wide open CA and out west, 3.55 and higher gears are pretty much worthless unless you keep the car on the track. BTDT. 55 mph cruising speed is lame. One of my favorite GTO's was a '65 with a 326 that was built up and an M-20 4 speed. That car was a blast to drive and ran great everywhere. It had a 3.23 posi out back. Again, IMO, the perfect 'compromise' for a stick car. And for me, fun.


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## Bob 69 vette (Sep 18, 2021)

Thanks for all of the comments. I pulled the diff cover and determined that I have a 3.36 ring and pinion. Question: with the Muncie 4 spd and 3.36 gears, how many teeth (or what color) speedo cable gear (the gear that drives the speedo cable and is mounted in the hole in the side of the trans) should I be using to get an accurate MPH reading?


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## Sick467 (Oct 29, 2019)

Bob 69 vette said:


> Thanks for all of the comments. I pulled the diff cover and determined that I have a 3.36 ring and pinion. Question: with the Muncie 4 spd and 3.36 gears, how many teeth (or what color) speedo cable gear (the gear that drives the speedo cable and is mounted in the hole in the side of the trans) should I be using to get an accurate MPH reading?


Bob, I commented on the thread you started on this subject to help get you started...









Which speedometer gear?


1967 GTO, 400, 4 spd. I pulled the diff cover and determined that I have a 3.36 ring and pinion. Question: with the Muncie 4 spd and 3.36 gears, how many teeth (or what color) speedo cable gear (the gear that drives the speedo cable and is mounted in the hole in the side of the trans) should I...




www.gtoforum.com


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