I am looking for info on converting my 390 into a 410 Mercury. I know that I will need a 428 crankshaft that is externally balanced. But where do I get the low compression pistons for this conversion? What other parts do I need to change in order to make this conversion correct?

i have started with the same convert. do you have a 410 short block? if so it will have a 428 crank in it.

I used Probe Pistons in my 428. I went with a 91/2 to 1 compression ratio. These pistons were recommended to me by the machine shop I used and another FE guy, they are supposed to have a better skirt than some of the others on the market. I believe they are out of Spokane Washington, I can get more info if you'd like.Good luck Mel