if its the factory 10 bolt i wouldnt go spraying it off the line with a sticky set of tires on it. especially if your flashing the convertor. i run a 7.5 10 bolt with moser axles and an auburn carrier and still come out of the hole at a low rpm 2200 and peddle her out for the first 20 30ft. ive blown up a a 7.5 with a street tire launching the car in a parking lot. ive heard horror stories about them on factory stock 305 cars which i dont believe. theyre weak kneed but not that bad. if its the 8.5 its a good rear but you probably still shouldnt hit her hard off the line on a sticky tire. i was looking into dana 60s and an anti balloon plate convertor to spray the car off the line and come out at a decent rpm (this has been put on hold for now since i passed the car on to my nephew. when i get it back its on.) post pics if you wind up getting the car.

 

one of the reasons the l69 305 engine was detunes for the monte as compared to the camero/ trans am is because it was lighter than them. with the same amount of power the the g-body is quicker than the camero. with the camero costing more this would not work for sales, the weights are valid

 

My weight for 83 monte was 3250 before mods and motor swap.so SS definitely about 3500