I have a Corvette with a Supercharged and Nitrous Injected 406 it cranks out a little over 1000hp. I drive it on the street so most of the miles are not that hard but i like to feel it go sometimes I drive it hard so at times it will see oil temps in excess of 300 degrees. I have been using 15W50 M1 but since it seems that they now use GRP3 base stock I'm looking to go with something else. I want to use a multi-grade oil so single weight racing oil is not what I want to use. What oil will give me the best protection and yet work well for cold starts and general street driving yet hold up to some extreme abuse. I change the oil every year car is only driven in the summer so it gets about 1500 miles between oil changes. Price is no consideration just the best oil for this application. What would you suggest.