Torque Monster !

The 413 can pull the A500 ratios with ease. But I would hesitate to use them with a small block.The ratios are
2.74-1.54-1.00 w/splits of .562-.649-.69od w/ the A500 ;as compared to
2.45-1.45-1.00 w/splits of .592-.690-.69od w/ the A518.
So shifting at 4000 say, the rpm drops are to; 2248 /2596 with the A500, versus 2368/ 2760 with the A518
But if using the 360 and shifting at 5000, the drops will be to; 2810/3245 with the A500, versus 2960/3450 with the A518
As you can see, there is not a whole big bunch of difference