Not necessarily after fit. The lighter weight is a plus but, I’m mainly after engine characteristics. I LOVE the free spinning nature of the 340. I’m hoping to achieve the same characteristics with extra cubes for a bigger punch
On a quick overview of the 340 to your offset low deck crank build, they’re kind of similar with big bore and short strokes. I’m sure the low deck will spin quick and high.
Considering the low $5K budget, home porting OEM cylinder heads seems like the best option. Also @ .474 lift, the best and most gain you’ll find in flow is in the bowl area and short side. After that, I’m sure you’ll find gains in flow but not a lot and I’ll call it not worth the pursuit. Once you go up into the port, it’s focusing on high lift/flow areas.
I’d bet even a set of new valves would be within the budget and really help a lot.
