Is there an identifier on the Rear End Axle assembly that shows Posi vs. non-posi, and gear ratios? It appears to have a 10-bolt 8.5 inch rear with 2.78 gear ratio.

I have a 1976 Chevy Impala Custom 2dr. that was my fathers.  He passed away four years ago, and I have been restoring it ever since.  On a very low budget the factory 350sb and 2-brl carb has been warmed up to about a 357cu.in. motor at about 300hp.

The Factory interior had a bench seat and Column Shifter. It now has new carpet, dash, bucket seats, center console and horseshoe shifter.  And 3600watts of ground pounding audio.

Time to get posi to the rear wheels. But on a shoe string budget, what do I need to get to change the factory pumpkin over to a road ripping posi?

Any help would be appreciated.

Thanks.
EJ