i have 2x7.4l 330hp's with 19p mirage props. @4500 rpm the boat reaches 49mph its a bit of a heavy boat with a deep v and no steps, italian make "C&B - shaft, 34 foot". if i repower with 8.2L/415hp's or 8.2L 502cid/502hp what should i choose as my props on bravo 1 drives?

you will up your rpms and speed with the larger hp engines .also worth trying 21p 4 blade s/s props if the boat is that heavy . you should be able to get a pair of trial props from your local mercruiser dealer