Serious 340 build into 361 HiRPM Screamer

Good thing you have the lifters. Schubeck sold out to "Smith" many years ago, but I havn't heard anything about them for several years. (Not Smith Pushrods or Clay Smith.) People either love them or hate them. No cam break-in concerns and it's actually better to run more spring pressure than required than taking a chance on not enough (Avoid valve float at all costs.). If something goes wrong and they shatter, the little super-hard shards damage most on the internal parts.

I've run their hydraulic & solids in my NHRA and IHRA Stock class cars without a problem. But a few haven't been as fortunate over the years.

Is checking/correcting the lifter bore angles & clearances an option worth considering.

Direct Connection use to sell cranks around 3.454" and 3.51". But it's beeen decades and don't know if any may be still stashed away. That's a big offset grind otherwise.

Would destroking an aftermarket 318/340 main 3.58" stroke crank offer any strength advantages worth considering? Not sure how the forging material would compare.

Rods look light and pistons probably "featherweight"?