I'd be curious why tho. I've been doing research on my truck to do the 4d55 build but havent heard of guys running into this issue when over boosted. Most are running intercoolers and larger exhaust also. They say EGT is your enemy on that engine and if it's running high EGTs that could cause the gasket to fail prematurely. Main reason for the intercooler and better flow exhaust is to drop those temps.