Father knows best!!

the old Ultradyne 223/231 on 108 in at 102 would be about as big as I'd go there and that'll work with the vert and gears, the LD 340 is a good one but if the crosswind is the airgap clone you won't tell a bit of difference between them

Overcam and undergearing a short stroke motor is not a good idea, if it was a stick and 4.10's the 508 would work a good bit better but I'd step that up one notch of the ultradyne chart to the 231/239 which is my favorite hot street 340/360 cam.