[mikana69]

Hey guys i'm looking for gears for my 67 chevelle. It is a 454 with a 4 speed with 3:35 gears in it now I have a couple fast cars for drag racing and what have you but this car i"d like to just make a good cruiser. The way it is now I never use first and if you ride the clutch at all i can bypass second so in doing the math if i went to a 2:43 it would drop the rpm 1000 at 70 which would make freeway speeds way more comfortable and i might actually use first gear again If you have or know anyone with 2:43 gears for a 12 bolt rearend please message on here or call text or email 715-205-8520
Thanks in advance
Dusty
[email protected]

 

[big gear head]

I think that would be a huge mistake. I believe you will ruin the clutch doing that and make the car difficult to drive. I wouldn't go past a 3.07 with a 4 speed unless you have a ST10 with a 3.42 first gear.

 

[DZAUTO]

I think that would be a huge mistake. I believe you will ruin the clutch doing that and make the car difficult to drive. I wouldn't go past a 3.07 with a 4 speed unless you have a ST10 with a 3.42 first gear.

Freddie is right, BUUUUUUUUUUUUUUT, in our 70 with a healthy SB400 and wide ratio Muncie (M20), the car used to have a 3.07 12bolt posi, and did just fine from a dead stop. NO, it was not a rocket from a stop, but clutch was almost non-existent
Over a year ago, I replaced the 3.07 12bolt posi with a 2.73 12bolt posi. The strong SB400 has plenty of torque from a stop to do the job. Actually, I would rate it about equal or better than a well built 396.The difference in taking off from a dead stop is VERY minimal, and Interstate driving is more enjoyable.
.Last year I also replaced the M20 (2.52 first gear) which had been in the 70 for many years, with an M22W which has a slightly lower first gear of 2.56.
My race days are over, so I no longer have a need for rocket acceleration from a dead stop. I need lower rpm's and fuel economy. I feel our national leader is going to assure that gas prices just keep going up and up!!!!!!!!!!!!!!!!!!!!

 

[mikana69]

I think that would be a huge mistake. I believe you will ruin the clutch doing that and make the car difficult to drive. I wouldn't go past a 3.07 with a 4 speed unless you have a ST10 with a 3.42 first gear.

 

[mikana69]

Hey thanks for replying to my post. So I'm not saying your wrong just trying to better understand what your saying The reason i feel that these gears would be ok is the 454 that i have is ratther healthy no a crazy big horse but rather impressive for power. I dont drag race this a all and you literally can't use first if you did before you had the clutch out your pushing it baclk in. Second gear taking off really feels to low to be just a regular driver i mean you can nearly take off in second with giving it no gas at all. This is why i said if you mess up and have it in third you can honestly take off without the average person even knowing that you were in third. I just had my trans out for a leak and they had to repair the case where they stretch the mechanic i had said its very common and he said that i have a early model 4 speed muncie like 66 and older if that makes sense and tells you what he gear configuration is The part i liked about the 2:43 gears was that instead of 3000 at 70mph it would be 2000 which is the perfecr rpm for that big block to purr and not feel as if an hour long trip is hard on it. Even though i know that it isnt hard on i at that rpm i just would rather drive my newer vehicles that far rather than listen to the motor turn those rpms. Does any of this make any sense?

 

[mikana69]

I also don't have to keep them in if I do infact find a set of them. If i tried them and then they didn'tt work I can always change them from there. I could do a 5 or 6 speed trans but the car works so well with the combo it has that its a shame to spend the money on a different trans when you can change the gears and make it work rather well and use the saved money on the blower and fuel injection for my 64 pro street or twin turbos for my 77 c10 with a 468. There lies the problem is having to many toys i try and decide which upgrade fits the build better. This car is just going to be a good driver is all i have planned at this point in time anyway. Sorry if i talk in circles sometimes i hope that you guysd can make sense of this and stear me in the right direction.

 

[cage2592]

Agree with BGH. Tom as well if you have the TQ/HP to cover a 2.XX gear. But at that low, you better be well past stock TQ.

Your first gear is either a 2.20, 2.52 or 2.56. Either way, you are still left with a 1.00 4th gear in all Muncie's. With a 2.43 rear gear pulling from a stop is going to be horrible. Lowest I've had was a 2.73 and I didn't like it, even with plenty of low TQ. HWY is where I drive 80% of the time and I went up to a 3.00 rear (9" rear).

If 70 MPH is your gauge, you should be around 2800RPM now @ 70 with the 3.35s. Going to a 3.07 as BGH suggested will put you 2550RPM @ 70. Plenty low enough and a good compromise.

Mike

 

[shovelrick]

My good friend had a 70 Camaro with a blown 496 & 4 spd but I can't remember which Muncie but had a 2.73 posi and it was fine driving through the burger joints and a blast on the freeway just cruising along passing everything around him, I even thought it was an odd combo till I rode around a few times with him, he liked 100+ mph on the highway

 

[72mojave]

Good torque and a numerically high first gear can pull off a rear gear ratio numerically lower than 3. But I think you really need to have both of those elements.

I have a 409sbc with a mild roller cam (224/228, .510/.510), a Richmond 5 speed with a 3.28 first gear and 1.0 fifth gear, and a 2.73 12-bolt posi with 27" tires. I haven't driven it with the 2.73 yet, but I changed it over from a 3.08 10-bolt peg leg. That means it went from about a 10.0 overall first gear ratio, which many consider "ideal" for street performance, to 9.0. Personally, I thought 1st gear wasn't very useful, but I also haven't raced. I'm thinking I'll have enough to get the car going from a dead stop and be pleasant to drive at 75 mph to keep up with the flow of traffic that seems to be getting faster each year. The cam is small for the motor, but I was looking to capitalize on the torque potential and I don't get past 5k rpms much.

 

[DZAUTO]

Agree with BGH. Tom as well if you have the TQ/HP to cover a 2.XX gear. But at that low, you better be well past stock TQ.

Your first gear is either a 2.20, 2.52 or 2.56. Either way, you are still left with a 1.00 4th gear in all Muncie's. With a 2.43 rear gear pulling from a stop is going to be horrible. Lowest I've had was a 2.73 and I didn't like it, even with plenty of low TQ. HWY is where I drive 80% of the time and I went up to a 3.00 rear (9" rear).

If 70 MPH is your gauge, you should be around 2800RPM now @ 70 with the 3.35s. Going to a 3.07 as BGH suggested will put you 2550RPM @ 70. Plenty low enough and a good compromise.

Mike

What Mike said is absolutely correct!!!
If you want to have a high geared rearend with a manual tranny, you need to have a good torque motor-----------------and that DOES NOT necessarily mean a nasty BB. The SB400 in our 70 with a 2.73 rear does just great.

 

[DZAUTO]

Good torque and a numerically high first gear can pull off a rear gear ratio numerically lower than 3. But I think you really need to have both of those elements.

I have a 409sbc with a mild roller cam (224/228, .510/.510), a Richmond 5 speed with a 3.28 first gear and 1.0 fifth gear, and a 2.73 12-bolt posi with 27" tires. I haven't driven it with the 2.73 yet, but I changed it over from a 3.08 10-bolt peg leg. That means it went from about a 10.0 overall first gear ratio, which many consider "ideal" for street performance, to 9.0. Personally, I thought 1st gear wasn't very useful, but I also haven't raced. I'm thinking I'll have enough to get the car going from a dead stop and be pleasant to drive at 75 mph to keep up with the flow of traffic that seems to be getting faster each year. The cam is small for the motor, but I was looking to capitalize on the torque potential and I don't get past 5k rpms much.

My Cutlass also has a Richmond Street 5sp (3.27 1st gear, 1:1 5th) and the original 2.41 rear behind an Olds W30 spec 455. The combination works great.
But, with that said, Olds engines are NOT typically top end engines like Chevy engines. A 455 Olds is a long stroke, long rod engine (Olds rods make Chevy rods look like a lawn mower rod), thus, an Olds 455 is a strong low-mid range torque engine, which is great for normal driving and strong from a dead stop. With a 2.41 rear, I have no clue how fast it would go on the Interstate!
And it's a great tow vehicle.

 

[bracketchev1221]

I would pick a gear that keeps the cruise rpm just around 2000. I know low rpm sounds great but oil splash and longevity are better a little higher in rpm.

 

[O'Man]

Hey thanks for replying to my post. So I'm not saying your wrong just trying to better understand what your saying The reason i feel that these gears would be ok is the 454 that i have is ratther healthy no a crazy big horse but rather impressive for power. I dont drag race this a all and you literally can't use first if you did before you had the clutch out your pushing it baclk in. Second gear taking off really feels to low to be just a regular driver i mean you can nearly take off in second with giving it no gas at all. This is why i said if you mess up and have it in third you can honestly take off without the average person even knowing that you were in third. I just had my trans out for a leak and they had to repair the case where they stretch the mechanic i had said its very common and he said that i have a early model 4 speed muncie like 66 and older if that makes sense and tells you what he gear configuration is The part i liked about the 2:43 gears was that instead of 3000 at 70mph it would be 2000 which is the perfecr rpm for that big block to purr and not feel as if an hour long trip is hard on it. Even though i know that it isnt hard on i at that rpm i just would rather drive my newer vehicles that far rather than listen to the motor turn those rpms. Does any of this make any sense?

No, it doesn't make sense to me.

 

[AZCamino]

Aftermarket Muncies with 2.99 first gear are available if you need more gear with the 2.43 rear. I think that is the M22Z option.

 

[hydro462]

Some were along the way people quit looking at piston speed...