Gear recommendation???

[mopowers]

Whats a good gear for the 8 3/4 in my 68 Dart 340? Engine is mostly stock, but fresh, purple shaft cam and X heads. Tires will be 255/60/15 (I believe 27" tall).

I'm thinking either a 3.55, 3.73 or 3.90. I've got a 3.23 third member now that I have to rebuild. So, I could stick to those. Just figured I'd put a shorter gear in it while it was apart.

The car's just going to be a cruiser and not see much freeway time if at all.

-Thanks

 

[1968dartman]

I have 355 gears in my 68 with shorter tires than what you are going with and love them! I rev 3000 RPM's at 60 MPH

 

[srduster340]

I'd go 3.90's. If it was a 360 I'd go 3.55.

 

[OldmanRick]

Very general question, so i have to give a generalized answer.....

.474 or smaller purple shaft.....3.55's would be a great overall gear.

.484, .508/.509 or larger cam.............right to the 3.91's for me.

 

[mopardude318]

i like the 3.55 gears behind my hot street 318 and 904 combo...works very good

 

[younggun2.0]

why not get the best of both worlds and go with the 3.73?

 

[fishy68]

Very general question, so i have to give a generalized answer.....

.474 or smaller purple shaft.....3.55's would be a great overall gear.

.484, .508/.509 or larger cam.............right to the 3.91's for me.

Totally agree. What the other guys are missing is exactly what cam is this "purple shaft"? Saying you engine has a purple shaft says no more than saying you have a V8 because their are numerous "purple shafts" ranging from very mild to all out race.