IIRC Ross still offers HC pistons, CR not known.
A pop-up piston must be made in 2 handed sets of 3, since the exhaust bump is on the other side for paired cylinders.
I would guess that a piston would be the bigger seller. If the pin boss is made thick enough the same casting could be finished to either 235 or 261 pin size. I doubt a forging is needed for the conservative engine speeds.
There is no available piston to use with the GMC rod, both for compression distance and pin size.
There is a huge minimum to be sold before the costs are recovered. As said or light bulbs: the first one cost $100,000,000., after that they're $1. each
IMHO a new rod is going to fall outside the budget of most builders. More length requires a new piston, $$.
The 261 rod is apparently safe for moderate performance use, the only defect being the pin size, which means custom pistons or only use in bores 3.75" and larger.
All of the other existing rods that look useful have the wrong journal size, length, or width.
