The Schubeck flat tappet option is the most solid solution to the flat lobe problem and also offers an option to overcome the potential problems with link bar type hydraulic and solid roller lifters (KISS principle).
I have had link bars come undone on the dyno, the lifter turns and ruins the camshaft - and your day. The Schubeck type flat tappet option eliminates any potential problems with the troublesome link bars used in the drop in hydraulic roller conversions. Schubeck type hydraulic lifters ($640) + hydraulic flat tappet cam ($70-$160).
Drop in hydraulic roller lifter kit ($350-$450) + hydraulic roller camshaft ($250-$400).With the increase in popularity of the drop in hydraulic roller lifter kits it is interesting to consider the price difference between using Schubeck type lifters on a flat tappet cam vs using a roller lifter cam and lifter combo. Use Schubeck type flat tappet lifters on any normal flat tappet camshaft.Convert to hydraulic or solid roller tappets.Amsoil confirmed as of 2-2-07 this oil will work with flat tappet cams, it is not a CJ-4 oil. This oil has the added benefit of increased rust protection which is ideal for engines that don't get run regularly and/or get stored. Use a good off road synthetic diesel engine oil like Amsoil 15W-40 Marine oil.See this page for test results and a link to purchase Amsoil products at the Amsoil online store through RevSearch Amsoil Dyno test results. RevSearch has documented power gains in testing Amsoil vs petroleum oils on the dyno.