1. When the head comes off, get it skimmed, replace the head bolts as they are stretch bolts and can not be re used. Also get them to replace the valve oil stem steals. 2. Get a standard head gasket. Victor reinez. 3. Get a proper remap. Stealth or united Motorsport are the peps too talk too. Ecu can't learn it's self due to motronic being crap and not advanced lol 4. Yes you would need to strip it again, and it's around 2500 rpm with a diesel 5th gear. Hope that helps