248/263 dynaflow will it bolt to a 320 that had a dynaflow?

[48buickkid]

i have a 48 roadmaster with a dynaflow i keep hearing about how the 53 dynaflow will make the older cars better problem is in 53 the 320 was gone and the bolt patterns are different so what im asking is what could i do to get more performance from this trans? i've heard its all about the 53 torque converter but i bet some some of the internals were upgraded also.Lastly if i wanted to purchase an aftermarket shifter would one for a powerglide work or not?