1975 Caprice rear end gear/rear end swap?

[Topless75]

I have a 1975 Chevy Caprice. I've seen some post that are somewhat similar but did not find exactly what I was looking for so this is my problem. The car's current features include 400 sb, bored over, high rise intake, headers, upgraded trans with shift kit, and a few other extras. The rear is stock and I want to change it in order to further increase my performance.

First off, I definitely want to put in a gear. I drive the car to shows so it is mainly driven in the summer and parked in the winter. I may travel distances up to 2 hours to attend shows and i am pulling around BIG rims (which I know is a factor when considering a gear ratio). I'm aiming toward 3.73/3.83 but also have had suggestions for a 4.11 so that is what I am first trying to decide.(it currently has factory gear ratio whatever that is?)

The current rear is an 8.5" 10 bolt rear with a 5x5(5x127) bolt pattern.

Next, I am also contemplating doing an entire rear end swap to make it a posi. I know 94-96 impalas have same bolt pattern and may work(but hard to find)? Upon research, other options that I've ran across include(all 2wd) 1988-98 1/2 ton full size chevy trucks, 1992-99 yukon/tahoe, 1985-02 astro/safari, 1964-87 full size buicks(electra/sabre/riviera hard to find).....and some others. I've run across a few parted out Chevy 1500s (currently looking at a 1988) and trying to figure out if this will work for my application?

Basically I am trying to decided the best/most reliable/inexpensive way to achieve my upgrade. There are also posi untils that I've seen on sites such as ebay and other retail sites and a gear must be purchased separately so this makes it rather expensive and don't know if this is even the most reliable. The posi rear is not a MUST but I figure why not if i can do is for the same price as the gear alone.

Your insight is greatly appreciated! Thanks!

[mike561]

good luck trying to find an answer on this site this site has started to rly suck idk why i even still come on here

[Blt2Lst]

Originally Posted by mike561

good luck trying to find an answer on this site this site has started to rly suck idk why i even still come on here

^^ I'm Not feeling the love here..

[mike561]

well back when i first signed up to this site it was really helpful, id make a new post and within an hour or so id have a response now it seems ill be lucky to get a response within a day or 2, i know not all of us are mechanics but some of us still know more than others which makes this site helpful