Limits of an Edelbrock performer and 1405 600cfm carb

The magnum converter is a lock up type, extra shaft inside input shaft will keep it from seating on 727 pump. I have never personally removed the weights but in theory, yes it should work.

The 5.2 will work much better, step up one notch in cam, regrind and old roller lifters will work fine. Throw on a new timing set and you should be good to go. With that combo, you will easily hit 300 and depending on cam size, 325. Dont go over .500 on cam without swapping out valve springs. You have a .439" lift now. Pm me if you need a cam that will work with what you have.