I sent a piston from a Touota to Ross Pistons. Durable enough for turbo/nitrous use. Pretty pricey though.
I'll give you a Felpro part# for head gasket/seal kits. I called a local Auto Zone searching for head sets, they have them in stock at the warehouse. It was a listing for a 351 V6, so multiply that by 2.
A place called Egge machine produces obsolete engine parts. I'm sure they could produce a set cheaper than anyone else. I think they only offer cast pistons. TRW might be a good choice for something more durable (if it's on a stand, how durable does it need to be???????).
If I ever have mine torn down to the bare block, I will surely have the internals balanced. Then there would be no fear of turning up the RPMs. I plan to eventually put mine into a vehicle, I'm just not sure what kind to look for.
Jay Leno has a fire truck, and he said it had a V12. He didn't go into any detail about the truck, he was in an interview on one of his other vehicles.
I've heard that the bigger old fire trucks were powered by the Twin.
