Any piston is going to cost if they are worth their salt.
Down by Russes is a machine shop called O’Reilly automotive they turn my 427 crank main journals down for 34 8\409 block and It cost me $225 to have it ground to MOT and magna fluxed. The rods cleaned up at .010 big block Chevy diameter. Just needed polished. Only problem is it took me about a month and a half to get it. They grind cranks in groups and there’s not too many W motors Out there needing ground.Pistons would have to be custom[about 1,000] but the 6.385 rod is common enough.A new 4 inch crank is about 800.so the cost wouldn't be outlandish.
Going with an Eagle 4" stroke crank. Not sure which rod I'll be using yet, but it won't be anything stock.Hope you don’t use stock rods! Especially if you put a 348 crank in it
Down by Russes is a machine shop called O’Reilly automotive they turn my 427 crank main journals down for 34 8\409 block and It cost me $225 to have it ground to MOT and magna fluxed. The rods cleaned up at .010 big block Chevy diameter. Just needed polished. Only problem is it took me about a month and a half to get it. They grind cranks in groups and there’s not too many W motors Out there needing ground.