The lim is a pretty PITA job on the 3100... You will definitely NEED the rocker arm tool, trust me! Do your research first because you'll want to have everything handy.
Used the stop leak on the 3100 knowing what a PITA it was to take it apart for the lim job (yes, lazy), kept it sealed until the front cover started leaking... Pin hole leak at first that leaked just enough to burn off without finding anything wet, but losing coolant. So thought it was burning it or head gasket. But then the front cover gasket really gave out and was easy to find the problem. Lol... So the moral of the story is try and find the leak, positively, where it is from. Clean the engine and let it dry, pressure test collant sys, compression test cylinders (head gaskets) and whatnot. If you find its the front cover and decide to do the job, you'll need the right tool for the balancer pulley... Another PITA... A day for each, or a nice weekend for both at same time. And yes, if you really let the thing overheat, the heads on 3100 are known to warp, but that'll show itself pretty fast. If you used the stop leak, and fix the lim or cover, I would flush the system pretty good and replace coolant getting rid of Dex crap. Change the thermostat too while it's all apart because that too is a PITA to change later...
anyways, good luck!
: )
