Here's an idea, but it means having a set of custom forged pistons made, and you're talking at least $600 for the set.
But since the small block Chevy rod is the right diameter on the big end, you can order a forged 6.25" set, which is about a half inch too short. But to make up for it, you could increase your compression height about a half inch since you have to get custom pistons anyway. That would be a compression height of 2.60" exactly.
It's just a thought, but diesel pistons are serious pieces that are made for compression ratios over 18:1, and often have a high compression height. I wonder if there's a diesel piston out there that measures 3.76" to 3.82" in diameter with something close to a 2.60" compression height. If you want higher compression, increase the compression height.
The only thing is the weight, probably would exceed 900 grams per slug.
The stock rod/stroke ratio is 1.64, which isn't bad for a motor with that much stroke. That's about the same as a 350 small block Chevy.
But the 6.25" rods would give you a rod/stroke ratio of 1.52, which is about the same as a 454 big block Chevy. So you'd still be safe to at least 6200 rpm with a good set of forged H-beam rods.
Aside from that, I wonder if any of the reputable connecting rod companies would consider making a custom set.
