I found this.
http://www.rcuniverse.com/forum/m_7403072/printable.htm
Read the second post.
BY the way the 3.3 comes shim from the factory for 33%.
If your tuning is right your engine shouldn't wear out fast. My friend as the 3.3 4 tec running 30 o.d. with about 9 gallons and it still running strong. Its all in the tuning. He's motor has never seen temps above 225. Ever.