3:42 vs 3:73 gear

[Bar50]

Here is something else to consider, the torque converter/stall in most GM automatics has roughly a 10% gear reduction in it. That is why automatic cars would have say a 3.42 and stick cars would have a 3.73.
If you go with the lower ratio gear(bigger number) you can always add a taller tire to raise the overall ratio some. Vice versa, you can use some shorter rear tires to see what its like to have a lower gear...follow me? Like 26 inch tall slicks versus 29 inch tall ones.

In town racing, the 3.73 will 'feel' snappier. Score some sticky tires, you'll impress everyone, well, some.

Next comes an airbag in the passenger side rear spring, IMCA tires or drag radials. Some drag shocks. A stall converter. Then some pepper spray, say just a little o' 125HP plate.....it never ends. Thats the best part!

 

[406monte]

Well, i had 3.42 gears in my monte. It came with 2.29 gears and that was just great for one the highway but not to good for launches. Well, i had a set from my 78 Monte left over so i put them in my 84 and i really liked them alot. They were fun for romping on the street and running on the highway cause it would really get up and go. It really made my stall converter react well to. I went to a 3.73 gear strictly for the track and wasn't disapointed at all. It did however raise the rpm's on the highway to around 3200 at 55 mph. I don't like running it that high for extended periods of time. I am going to a 4.10 gear in my 12 bolt because it is basically a track car now. If you stay with the 3.42 gear you will be overly pleased and it will give you good performance for what you have in mind and save you some gas money in the end.

 

[custom442]

I agree with a lot of these suggestions, you really won't notice the difference with that upgrade unless you have a real powerful machine. You could notice some difference on the highway, maybe two or three hundred rpms higher with the 3.73 but not much. Just think of it as money you can spend elsewhere on the car.

 

[Phoenyx]

I agree with a lot of these suggestions, you really won't notice the difference with that upgrade unless you have a real powerful machine. You could notice some difference on the highway, maybe two or three hundred rpms higher with the 3.73 but not much. Just think of it as money you can spend elsewhere on the car.

I disagree. You put 3.73s behind a stock 305. It will feel like a rocket off the line compared to having 2.29s.

 

[bubba428]

3.73 all the way...its not really that bad on the street either.

 

[shotgun]

Not enough info to advise either way.

Need engine specs, convertor,trans, tire,vehicle type,weight etc etc.

Have you maximized what you have already?

Got it hooking hard?

"Power is nothing without control".

 

[406monte]

I disagree. You put 3.73s behind a stock 305. It will feel like a rocket off the line compared to having 2.29s.

Yea, that is abig difference in gearing of course it is gonna feel like a rocket ship. That would be like driving a chevette and then driving a nascar they are both night and day compared to each other.

I would still with today's gas prices stay with a 3.42 gear. If all you are goin got do is use it as a daily diver and an occcasional romp down the street or track. You can always use that money to go elswhere in the motor or car.[/quote]

 

[Phoenyx]

And I would like to add something else. As far as gas mileage goes. Mine improved after swapping in 3.73s. The city I live in has a lot of hills. So it could be because it's not working as hard to get up those hills now.

And I took it on a highway trip on boxing day. Not to far, only went about 2 1/2 hours each way. But only going 80kmh (50 mph). I went kinda slow because the car was fairly new to me at the time (and still is). And at that speed I was already pushing 3000 RPMs. Plus with a car full of kids I didn't want to find out the hard wat that my stock 305 couldn't handle a 2 hour trip at 3500+ RPMs lol. But anyway, that trip took lees than $20 worth of gas. And gas was about $1.10/litre at the time.

I'm not sure how the mileage would have been if I was going the speed limit, but if your not in a hurry, highway trips are possible with decent gas mileage.

 

[Larryg]

I'll be finding out soon enough as I'm going from 2.29 to 3.73. Its what it came with so I'll live with it. It still has the baby 6 so this should help a lot! Uphill on ramps were a chore!

 

[Phoenyx]

And here's something else you should know. It's gonna be about a $200 bill to get the speedo re-calibrated. And also. Your original transmission is set up to work with the gears that the car came with. After you put the 3.73s in it won't shift proper anymore (if you just leave it in drive). I guess theres some kinda governer that needs to be adjusted somehow. I don't know how hard or expensive this will be because I haven't had it done yet. But if ur racing around and shifting manually it won't mater. Will just probably skip 2nd gear under light throttle loads.