Adrian,
Honestly I couldn't tell ya. I don't have a OS .30 nor do I even use the stock roll bar. In fact not a whole lot on my MGT is stock anymore.
I will say this, I wouldn't bank on a wing or wing mount to protect my engines head. Either get a really nice roll cage from RC Solutions or get a custom made roll bar. I believe a member here by the name of The Dude makes roll cages, you might want to email him.
-Michael