stock 81 monte rear end to what gear???

[my81montecarlo]

have a stock 81 monte rear end and want to upgrade to a different gear set up.it has a 289 in it now and wont even turn a tire,I have a 95 350 with a 280h cam for now that I'm swapping in.I'm going to install a mini spool but was wondering what size gear to go with?would I have to install a gear spacer to put 3.73 in it?
tire size is 255-65-15

 

[Doober]

You have 2 options, either a thicker 3-series gear for a 2-series carrier, or a spacer. I'd prefer a thicker gear because the spacer is just one more thing to move around (although it shouldn't). A support cover would be a good investment as well.

 

[my81montecarlo]

would 3.73 be a good set or 3.42?its got the 200r4 and I'm looking for a quick launch.although its going to be a street machine with a roller cam and 142 blower set up in the future

 

[my81montecarlo]

and does any one know what the stock gearing is?

 

[86montecl]

the stock gear in my 86 is a 2.41 thats RPO code gu1.

 

[Doober]

At the shortest I think a regular Monte with a 2004R is 3.08, the SS had up to a 3.73.

For performance, I think a 3.73 would be great, just make sure you have a posi or you're going to waste it all in tire smoke I have a 350 making near 375hp, it has a 4-speed and a 2.29 (math makes it about equal to a 2004R with 3.42s). Let out the clutch at roughly 1200rpm and it'll spin all the way through 1st with a peg-leg.

This video was rolling into the throttle at 5-10mph.
http://www.youtube.com/watch?v=FwI9H1p574Q