My GD is according to Ariens is a 99-00 model. It appears to have original motor. Great Dane 25 decal on it anyway (spec sticker gone as was the top plastic shroud) Pulled the motor as I knew head gasket was leaking big time. After removing the heads could see gaskets burned through in several places. Even had exhaust carbon on head stud/washer..But this is my few surprises (since these kohlers new to me and am not a mechanic): I have studs instead of bolts on a 99-00 model and I thought studs was a later upgrade. My valves/piston walls look emaculante..even can see slight cross hatching in bore, it appears so anyway- not one line. very little carbon build up except the light coating from running like crap with gasket out. And I thought sump used rtv (what I read) mine appears to have a gasket? I'm tempted to not touch the lower end since it appears clean and dry and just do lower seal and head kit. hate to remove gasket in sump if it is one..might need another look. These are what I got for numbers with the studs :Heads- 24494 removed head gaskets-2404137 P.S. noticed the worst side that the 2 outer head bolts were loose too.. could take off with fingers!