Anyone else consider or install a REALLY tall rear end gear to keep revs down?

[Scooter]

My Challenger currently has a 2.76 open which is not bad for highway cruising... but if I don't want people riding up my backside I need to still wind the motor up to 2800~3k on the highway. My Ford has a 3.0 nine inch with similar issues and I have a 2.50 ring and pinion sitting on the shelf I'm thinking of tossing in. Not interested in investing in another trans. Anyone actually installed tall RE gears... what was your experience? I know I'd take a hit off the line... but I do more cruising on the highway than trying to burn rubber around town.

[Rich G.]

How fast are you going that 2.76 isn't tall enough? I'm wondering if there would be that much of a difference putting in 2.50. I've never seen a set like that.

[gzig5]

Try a taller tire.  I've got a 29" tall tire on mine (255/70-15) and 3.55 gears.  I don't remember the tach reading but I didn't find it offensive on the highway.  An OD transmission is the best solution.

[Brads70]

I don't think you will notice enough difference between 2.50-2.76 to warrant the effort? Where are you driving 2.76 at 3000 rpm's? Salt flats?  If you go much lower number wise might have issues taking off in first?
In my car I ran into the opposite problem where with 3:55 engine/cam was " happy" at 85 MPH +but oddly enough the police were not?  So I installed 4:10 to bump up the rpm a little so cam didn't lug at 2000 rpm, now revs at about 2300 at 65 MPH.  I have an OD transmission

[7212Mopar]

2.76 is tall for a muscle car already. May be Gearvendor overdrive?

[7E-Bodies]

I just took out a 3.91 and put in a brand new 3.23 like my car was born with.

[Filthy Filbert]

Maybe you need a different converter that won't slip as much?   My Cuda had 2.76 gears and I could cruise at 70 mph with comfort.   Now, at 6500' Elevation, and a tired 2bbl 383; it wouldn't turn a tire on gravel....  But highway cruising was a breeze. 

[autoxcuda]

Just hit the pedal on the right.

3000 is not much.

This is 85 mph or so

[Scooter]

^^^ Thanks all. I've recently moved from the SF bay Area to Reno... drove the Ford here and back once and the Mopar one way. Maybe I'm just a bit oversensitive to it right now as I've put in a tonne of highway miles in a short stretch of time. I'm at 5000 feet or so now and still working on leaning out both cars. I've been thinking of replacing the torque converter in the Challenger as it builds a lot of heat on grades.. I do not think it is a stock piece and is working against the 2.76 rear.

[ledphoot]

For a street car I like 3.23 and 3.55 gears. My Cuda has 3.55's with a Tremec TKO, they have a low first gear so it's got plenty of grunt out of the hole, overdrive is nice to have on the highway. The Challenger has 3.23's, it was fine even when it still had the 833 four speed. Since your car is an automatic I'd stab 3.55 in it and get a gear vendors unit installed.

[Scooter]

Gear Vendoes is a nice setup... but geesus gawd the $$.

[GoodysGotaCuda]

How tall of a tire do you have? Going from a 26" to a 28" tire is worth about 5mph.

[jbaha]

or maybe just install a 5th gear? i'm at around 2000 at 75 mph  i know that's not the same project

[HP2]

I've done it and while it does improve highway cruising slightly it really negatively impacts in town driving and the fun derived from owning a classic car.

[Scooter]

^^ Thanks all. Not going to swap wheels and tires as everything fits and is new now with the 15 inch steelies & BFG's. I'm going to mull it over the winter and see if it's still bothering me at the end of next summer. the 2.50 ring and pinion I have is not going anywhere.