Reccomend me an axle ratio

[Steve/Bryce]

We hae a new 408 stroker with a new 4 speed and dual friction clutch.  The car will see little highway use except driving to a dragstrip.  Some street-light action, No car shows I want a driver.  It's not a sure grip so I'm in the market.

[MEK-Dangerfield]

Since you say you won't be doing much hiway driving, 3:91's and 4:10's sound up your alley...But the diameter of your rear tires comes in to play also.

[Steve/Bryce]

Right now we just ahve the origianal size on 14"   want to go bigger.   I'm guessing a larger tire size can handle a higher great ratio. i mean lower=4:11's

[Moparal]

I run a 410 dana in my car with a 499 build b engine.  My tire size is 27.5 diameter.  275x60x15   I definately do not have a hwy gear, im always cruising at 55 mph sometimes 60. 60 is around 3k or so.  I dont have any sure grips for sale right now Steve. I got yer PM.  I might sell my dana local, but not ship.   You do need a 15 inch tire on your car to get a better choice of tire under there

[bigblue73]

http://www.hurst-drivelines.com/index.php?option=com_content&view=article&id=193&Itemid=144

Here is an RPM calculator that we have on the website.  It's plug and play between the tire diameter and rear axle ratio.  Disregard the over drive since you are using a 4 speed, which is 1 to 1 in 4th.  The RPM's will tell the tale.

[bb71challenger]

If you have an 8 3/4 I would get what you want and use what you have now as highway gears. Takes about an hour to change the gears out. I ultimately want one set for cruising and one set for hot street driving. I have a 2.94 sure grip and a 5.13 but its too low. A 4.56 or 4.10 would be perfect imo. Of course that is with a 15" tire.

[vinb]

Here is another.....
http://vexer.com/automotive-tools/speed-rpm-calculator

[Road_Runner]

Unless you're going to be driving local (45 MPH or less) roads 90+% of the time I would strongly recommend not going any higher than 3.91 or 4.10.  I've run both in my Roadrunner through the years and even the rpms at 55 gets old after a while.  I just didn't like running that many rpms all the time.  Thats why I switched back & forth between a 3.23 chunk and the steeper geared chunk depending on whether it was racing season or not, I was driving extra for school or work, etc.  When I lived in the 'country' in middle Georgia I could deal with the steeper gears, when we moved to suburbs in Atlanta and I was doing regular highway driving the 3.23 chunk went in & stayed in.  I've heard others say they don't mind the higher rpms and that it doesn't hurt the engine but for me it was unnecessary wear & tear on what was a pretty expensive motor for the time.  That's why have plans for either a TKO 5 speed OD transmission or a Gear Vendor Gear Splitter with either a 3.91 or 4.10 rear gear for the Bird.  I'm not sure if I'd want to go back to swapping the chunks out, when I was 17 it was no big deal, now crawling under the car is not as easy or fun as it used to be! 

Later, Jim

[Steve/Bryce]

Thanks, I think I'l go in the high 3's  This is Colorado everyone drives 83 mph on the highway.  It's an hour to Bandimere (Denver) or the Pueblo dragstip.

[Road_Runner]

Thanks, I think I'l go in the high 3's  This is Colorado everyone drives 83 mph on the highway.  It's an hour to Bandimere (Denver) or the Pueblo dragstip.

If you're serious about 80+ MPH (And I can relate in Atlanta, think public bump drafting) I wouldn't go any steeper than a 3.55 and would seriously consider a 3.23 or OD setup like I'm planning for the Bird.  Again, not to say you can't go steeper but high revs for an hour drive on the highway get old fast...  Use one of the rpm estimators plugging in tire size, etc. and see what your rpm is going to be at that high of speed.  Until I swapped the 3.23 chunk back in years ago, I was relegated to the slow lane with people passing me constantly even then, not my idea of fun.  I'm thinking about either 3.23 or 3.55's for my 318 Barracuda or if I'm just flush with cash I might consider an OD setup for it as well.

Later, Jim