Why not just buy standard pistons?
What a novel idea. Though he is going to need +0.010" oversize I should think if he's melted the piston skirt.
Good point and there’s are no oversize XB pistons IIRC. Which then comes back to the options:
Secondhand top end
Hurricane pistons plus rebore
Hammer pistons plus rebore
Wiseco pistons plus rebore
NRHS 1250 kit
Hammer 1250 kit
Yep. Multiple choices out there. And at least over the pond there's usually folks selling on pistons + cylinders they have taken off for a 1250/1275cc upgrade. The very last thing the OP needs to be worried about is how the pistons are actually made.
*** I don't think either Hammer or NRHS make oversize pistons actually. I do have a set of cylinders at home bored to +0.010" by Hammer (with Wiseco 10.5:1 forged pistons
) but they are small fin cylinders not XB large fin cylinders.