Have a 2008 kawasaki 1500 with excessive noises from rear lifters, also noises cam chain slap, my mechanic keeps telling its normal. thanks

Ticking noises from an engine, even an SBC, are never normal, Richard. You may be hearing lifter noise (one bad lifter) or excessive valve lash, or both... or you MAY be hearing a small exhaust leak from one manifold. If the pistons you put in aren't a really good match for the cylinders, you may be hearing "skirt slap", which will devolve into a really bad situation later down the line when the piston skirts break off. You may possibly be hearing bearing rap from either rod bearings or main bearings, if they were a little too loose, or timing chain slap if the tensioner isn't working right, or looseness in the distributor drive, or even spark snap between a plug cable and the block or head.

sometimes automatic cam chain tensioners freeze up or run out of adjustment. if it's frozen up you can replace it with a new one. if it ran out of adjustment you can replace thecam chain because it stretched out or install a manual cam chain adjuster because they usually hve a little more room for adjustment.