Gear ratio question

[Barry Stewart]

Hey a newbie here. I have a 70 Cuda 440-6. I have a Dana with 3.54. I just put drag radials on and I'm looking for more " throw you back in the seat" feeling but I still want to do some 30 to 50 miles drives at 55-65. What's my best choice for gearing ? 3.90, 4.10? Tell me your thoughts, thanks

[ToxicWolf]

I used 3.73 because I have a 5-speed and didn't want it lagging at slow highway speeds.  What kind of transmission and do you know its gearing? 

[brads70]

This will help you figure your RPM's  at given speeds with different gear ratio's
http://vexer.com/automotive-tools/speed-rpm-calculator

Lots of factors to consider, cam power band, tire diameter, convertor slippage if it's an automatic.

[Barry Stewart]

I have a 727 built by CRT Super Street with a TCI Street Fighter converter. Tires are 28" tall. Purple shaft cam, not sure of left etc. would going from 3:54 to 3.73 make much difference? I know 4.10 is pushing it for what I do.

[brads70]

I have a 727 built by CRT Super Street with a TCI Street Fighter converter. Tires are 28" tall. Purple shaft cam, not sure of left etc. would going from 3:54 to 3.73 make much difference? I know 4.10 is pushing it for what I do.

RPM wise about 200 rpm more @ 60 mph

[HP_Cuda]

You will be pulling > 3k with that setup and over long hauls would get really annoying.

Ever thought of getting an OverDrive? Then you can step up to lower gears like 3.73, 3.91.

[Barry Stewart]

I would love an overdrive or a tremic 5 speed but not in the budget

[gafletch]

Brad, according to the reference, going from a 410 to a 355 would only reduce my rpm a few hundred at 65 mph. May not be worth the expense to change.

[HP_Cuda]

With a 275-60-15 rear tire and going from 3.55 to 4.10 you are going to see an increase of 400 rpm and almost 500rpm.

Heck with the 3.55's with that tire you are doing 3k at 70mph freeway speeds. Can get a bit annoying over long hauls.

[vinb]

I have a 3.55 with a 275/60/15  89" round tire actual rpm is 2850 at 65 mph with the 4spd.   Automatic may see 200 rpm higher.