what piston and compression is this?

[racer82]

i bought a 300 ex and it had this piston in it. i dont know who makes it or what size it is. it looks to be high compression but i dont know how high and what gas to run? any help is apprecciated!1718103209\

[LT80]

The markings make me think it's a wiseco.
It's obviously a .5mm oversize piston.

[racer82]

i cant find a product searcher for the numbers on it but maybe im not looking hard enough. Thanks!+

[racer82]

just found the product search. its not a wiseco

[LT80]

I looked at a few pics and part numbers and didn't find it either.
From looking, IMO, it's not a higher compression piston. Many look like the top of yours.
So about your octane question, I'd say 93 is fine. Altho a compression test will tell you the octane needed. :)

[gnccracer456]

i was thinking it looks like a 12:1. i dont really know though. what compression should i start running higher octane at?
Thank you alot LT80!

[miniquaddad90]

Wiseco 11:1 300ex piston. The #4574 gives it away. 93 octane will be just fine