4.30 gears ? Should I?

I just counted the ring and pinion, 43 x 10. I am not sure if I want something this low. I know it will be fun but freeway driving at 65mph is going to be what, 3400 rpms?

It will be behind my 273 solid cammed 4-speed cuda so I think it will help that little motor somewhat. The other option I have is 3.23 or go shopping for 3.55 or 3.91.

I have not picked out tires or wheels but will probably go with 17's and tall as I can get in the back.

Damn, more decisions.

Not going to be a daily driver. Lets year your opinion.

Oh, one more thing... is it ok to use rtv to seal up the housing or should i go get the gasket?