Looking to rebuild my 68 impala Rear end. Help!?

[Emeka N]

I have a 10 bolt 8.2 rear end in my Chevy. Someone told me its a ratio 2.73 if I remember correctly. I am putting new preformance heads, intake and a new cam. I was considering rebuilding the rear end or just buying a unit to swap it out

I dont know anything about the rear gears. Could I just buy a posi unit like below and swap it out with mine instead of rebuilding what I have? If so, which is best to go with? I just want it done, not worried about rebuilding it. Summit is saying my rear end ratio needs to be a 3.55 or 3.73.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ETN%2D19559%2D010 &N=700+115&autoview=sku

[tronary]

The ratio should be stamped on a small metal tag attached to a bolt on the rear end. The numbers you have provided don't make sense unless you are looking for low end torque and no speed. The numbers represent how many times the drive shaft turns for 1 wheel revolution. 2.73 is 2 3/4 shaft revolutions for 1 wheel revolution. Therefore a 3.55 or 3.73 would require more shaft revolutions for each wheel revolution. If you want to know for sure, raise the rear wheels and manually rotate drive shaft and count how many revs to turn wheel. Rebuilding a rear end and changing the gear ratio is a very exacting job and requires a book that shows how to pre load bearings and such. If not precise the rear end will howl or have other problems.

[tronary]

The ratio should be stamped on a small metal tag attached to a bolt on the rear end. The numbers you have provided don't make sense unless you are looking for low end torque and no speed. The numbers represent how many times the drive shaft turns for 1 wheel revolution. 2.73 is 2 3/4 shaft revolutions for 1 wheel revolution. Therefore a 3.55 or 3.73 would require more shaft revolutions for each wheel revolution. If you want to know for sure, raise the rear wheels and manually rotate drive shaft and count how many revs to turn wheel. Rebuilding a rear end and changing the gear ratio is a very exacting job and requires a book that shows how to pre load bearings and such. If not precise the rear end will howl or have other problems.