street gear ratio for 340 engine?

[CB]

I just looked up this detail: my car has a TF 727 with 3.23:1 ('69-'74) gears

Will it make a big difference changing the gears and go from 3.23 open to 3.55 or 3.73 suregrip?

I read that driving with 14' or 15' wheels and 3.91 gears isn't a good match?

It has the 318 in right now and it 'll have the mild rebuild 340 back in soon.
Thanks
CB

[Ghoste]

It really comes down to you and what you want from the car, but if it were mine I'd go with the 3:73's at least.  The 340 likes to rev so why not let it?  That's just me though and I tend to drive the car with enthusiasm.
As for not running 3:91's with a shorter tire, again, it depends on what you want to do with the car.

[CB]

plans with the Cuda: I want to build a weekend warrior not a semi drag car, cruise-in at 100 miles radius.

[Ghoste]

Well, it will make a big difference going from the 3:23 to whatever you decide but I'd still stick a 3:73 behind that 340 unless you plan to do a lot of high speed freeway cruising.

[CB]

I read somewhere changing only the gears isn't a biggie but going from open too posi would take some time, right?

[Ghoste]

Yeah, if you want to add a limited slip to it, you'll pretty much have to tear the differential down.  You can buy one already assembled and rebuilt with the gearset of your choice in it and save lots of time.  A little more money but you'll know it's set up right and ready to go.

[firefighter3931]

Christian, something to consider when choosing the gear ratio is your tire diameter. Taller tires will reduce the final drive ratio somewhat. The 3.73's with a 28in tire (275/60/15) would be a nice all around combination that you could live with on extended highway drives. 


Ron

[CB]

thanks Ghoste and Ron for your advise!
I have the 275/60/15 in the back so I'll get the 3.73's 
CB