Chang cams

That would be taking a step backwards. The cost for new pushrods would outshine the saving on flat tappet. Re-grind the cam. Bullet, Oregon, Hughes, etc.

Look here, I have a set:

http://www.ebay.com/itm/141520580056?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT