The new oils with the AMP marking just do not work on flat tappet enigne with 120 to 150 seat pressure and over 300 lbs open pressure. The engine they use to test with have no spring pressure andn no camshaft to speak of. I al tired of beating a dead horse, I do not care what you use I just know what works on high perforemance engines and makes them wear the best.
Personally if you do not buy an engine from me use what you want, if you buy and engine from me I will not warranty unless you use the Joe Gibbs. They also have the conventional
oil that we use call Hot Rod
oil that is about 6.50 to 7.00 a quart. Works great, I use it in my wife's 55 Chevy, My cobra's and my older Mustangs. I use the
synthetic in my 20,000.00 race engine that I turn 9000rpms and have had zero problems in three years. I rebuild and everything looked great. This is a dirt circle track engine that will get run much harder than most of you will ever run your engine.
We sell the Jo Gibbs and believe in it fully. Like I said run what you want as long as you do not get the engine from me and want it warrantied. We can agree to disagree and it will not be the first time or the last time that it has happened.