Rear Gear Recommendations

[Haney]

I have a 73 Cuda, 440, E heads, xe285hl cam, headers. Fairly stought little street car. it is a A-833 4-speed and has a 3.91 sure grip. Currently has 275/60/15s in the back (28") but will be going to 255/60s (27"). I am wanting a higher gear to make highway driving more enjoyable. Any experience with a this cam and 3.23s? Will it be a dog out of the hole? Currently I run about 3200 RPM at 65 mph. With the 3.23s the online calculators say ~2600 RPM at 65 with the 3.23s and 27" tire. Power band on cam is 2500-6500.

What do you think? If I had a gear I would just swap and see, but wanted some opinions since I have to buy a gear.

Thanks,

 

[fasjac]

If you want to do “say” more cruising at 65-70, go with the 3.23 gear. You can get away with a lot with the 4 speed as far as low end. An ideal gear may be 3.55. Really depends on how you drive the car. It won’t be a dog on the low end with the 4 speed. How often do visit the track or race anything on the street? JMO

 

[70chall440]

I completely agree with fasjac, 3.55's are a great "in-between" ratio but if you intend to do any significant highway driving (as in several hundred miles or more) 3.23's might be a better choice.

Here's the deal going from 3.91 to 3.23 will definitely feel "weaker" initially but I think once you get used to them I think you will like them. A 440 with a 4spd still has plenty of grunt and will be no slouch on the street but it might not be the tire fryer you are used to.

 

[Chryco Psycho]

I have no experience with that cam , I will not use them .

 

[Haney]

I am really on the fence here between 3.55s and 3.23s

 

[Rapidfire]

I go with the 3.23 for the highway. 3.55 is nice but not that big of change from 3.91 for the work to swap it over IMO.

 

[heminut]

I go with the 3.23 for the highway. 3.55 is nice but not that big of change from 3.91 for the work to swap it over IMO.

I agree with this statement. I've had both and for hiway use I prefer the 3.23 gears.

 

[Big J]

Just throwing this out there, what color speed gear for the trany . if it's a 727 auto 3.23 gear and a 3.55 gear ?

 

[heminut]

Just throwing this out there, what color speed gear for the trany . if it's a 727 auto 3.23 gear and a 3.55 gear ?

I never paid any attention to the color of the gear, I always went by tooth count. The tooth count number is cast into the gear. Believe it or not, with the size of tire I was running, the 32 tooth gear was what worked for me for 3.23 gears and the 35 tooth gear was what worked for the 3.55 gears!

 

[MoparCarGuy]

A couple of reference charts...