does anyone know if the 40 LA piston and cylinder would work in the 40 FP?

According to the OS engine parts site (http://www.osengines.com/parts/index.html), The P/L sets have different part numbers. Whether is difference is timing or size is unknown. Maybe somebody else can help. But what is strange is that OS also lists two different P/L part numbers for the LA.

the sleeve wont, the fp has a thicker sleeve, the pistons will, and the cranks interchange just fine

Look for an older Magnum 40 bushing engine, it drops right in and you get a chrome bore out of it.

thanks for the replys everyone,i think i will try the older 40 Magnum cylinder and piston trick, just because i have one and i will keep an eye open for replacement parts too.thanks again.