I am up here in Canada with a 1970 monte carlo, have had a gaggle of rocket scientists tell me about rear ends. I am aware that in 1970 Chev put 2 different rear ends in these, a 8.5 and 8.2. Short of pulling the rear cover and doing a measurement is there any sure way of telling the difference.  The car can be seen on the following website  conneryscustompaint.com   look under flames it is the black flamed monte carlo.   Thank you.

Don

Count the teeth on the input shaft (under the U-joint hub) 25 teeth and 1.44 inch dia. equals 8.2, which is the old design; 30 teeth and 1.63 inch dia equals 8.5, new design. From the outside both the 8.2 and the 8.5 come in the same size packages (10&3/8s or 11 inch housings and use the same gasket) so the housing gives no clue as to what's inside.

Bogie