What size brakes were on the rearend ? Assuming it was the original rear axle 11" drums would have been a drum brake car and it would have been 3.54 geared , 10" drums would have been a disc brake car , but it could have been either. Again assuming the original rear there is a number on the pass ide tube that telss how the rear was originally assembled.

That said you have a 493 stroker , get the 054 , the only one that will complain about it will be your wallet $$$$