It does depend on the plug your OHV series uses. The current design went back to the Champion RJ19LM style and is .030. The previous designs used the RC12/14Y with a .020-.030 gap if memory serves me correctly. Basically, it's a pain in the duff and we all get to fumble through B&S making that design work.
It's right in line with last year's 550e used a paper element filter and this year has a basic foam element.