I've got to replace the gasket between the rear & front case. I lowered it 4-1/2" & got all bolts out except one. Someone in- the- know will know which one. It's all original & the one about 11'o'clock & the opposite side has the bracket for the shift motor. This bolt is round & has raised grooves. I've never seen one before. 11 mm is close & 6 points works better than 12 but they strip. I tried a small vice grips which also strips. The only thing I can do is lower the TC all the way down & use a bigger vice grips. I however love heat in these cases. I use hand held propane / map gas about 2300 degrees I believe. My question is how much heat can aluminum take from propane etc. & not distort the aluminum.