Shawn,

Heck, I'd use it. It's a classic old-school 4-speed.

I had 3.55s in my GTO with G70-14 redlines (26.8" diameter) before I went crazy with it. It turned about 3100 at 70 mph. With the 4:10's and Mickey N50's, it was a different story.

Calculate your RPMs at speed using the calculator below and see what you can live with. Figure out your tire diameter, then play around with rear-end ratios. Do what makes you comfortable. Maybe a 3.08.

http://www.csgnetwork.com/multirpmcalc.html

One good thing with the close-ratio Muncie and a 327 - once you get rolling, there's a smaller RPM drop between gears.