Deleting and bulletproofing are not the same thing. Deleting almost always means disabling or removing emission control devices. Bulletproofing has become synonymous with the Ford 6.0s and refers to improving egr and oil cooler systems to prevent head gasket failures. Sadly every CL and Ebay ad now states that 6.0 Ford diesel trucks for sale have been bulletproofed but gee they don't have any proof of it being done or for the parts if they did it themselves. Or they use the term for GMs and Rams that never needed it in the first place.