1) The real issue is that you need a tune. Lowering the oil temps if they are not unreasonably high is a band aid.
2) I think you already have one, but if you don't I would go for a 160F thermostat.
3) What spark plugs are you running? This can make a big difference. I like the old school autolights. I will stay away from any platinum shit. The stay hotter which helps them last alot longer, but they are way more likely to detonate.
4) As a referance point for a similar motor: Normal friving oil temperature is about 200-215F, When I'm road racing oil the oil will get to 255F. With the new synthetic oils thier breakdown limits are so high that you would have other major failures before that point.
Go get a tune
