[acammer]

No reason not to do 4.10s. I've got a pretty good write-up on this. I'd encourage you to take a read through it.

https://gwatneyperformance.com/geari...1-manual-cars/

I'll also tell you from personal experience that 4.10s are a blast even in a bolt on car. You're getting more mechanical advantage in the lower gears, so more acceleration, and you get to bang another gear when you're accelerating onto the freeway, and you can even catch the 3-4 before triple digits (with a 6500rpm bolt on car sort of shift point). There really isn't a draw-back, you give up some cruising rpm, but it's still only 2,000rpm at 75mph - you might loose 1 mpg of highway economy, but I'm betting that's not why you bought the car. Unless you're on solid subframe and diff bushings it should still be pretty quiet as long as it's setup well.