problems
 

my truck never got at the temperature that it need it to, it never even got pass 140 and I dint really ever worried about it it ran fine and the other day I was driving down the road and it started knocking so I shut it off, I called a buddy and when I got it to the house I had oil in my radiator and i checked my oil and i coulnt tell if i had water in my oil but the oil lever is alot higher than what I had it, it still starts and everything. Do yall think this has something to do with the temperature never beeing were it supposed to? and the motor only has about 11 thousand miles my buddy rebuilt it not to long ago.

Well if you are mixing fluids I would guess either a bad head gasket or a bad oil cooler. I would lean more on the oil cooler if its the original piece.

Or your buddy installed the wrong oil cooler gasket in the wrong place, thers a couple different oil cooler gaskets in a 12 valve kit