rear gear ratio and posi suggestions

[kevncar]

Here's the low down. I'm looking for advise on what gear ratio to use and which posi carrier you guys suggest. I am running a 454 with a th400 and am going to put a used gear vendors overdrive behind it. It has a .78:1 overdrive. I'll be running a 295/50/20 in the rear.

I used a speed this speed analyzer...
http://www.keislerauto.com/tools/gm_analyzer_6sp.html
which has a .8 overdrive. So my speeds should be just a hair higher.

I'd like to have a pretty nasty bottom end to have a little fun with...but I want to be able to take the wife two hours away to IKEA and pickup the couch of the month also.

Any and all suggestions would be appreciated.