1985 K20 manual transmission. I just installed my second clutch slave cylinder in 2.5 years. Both gradually would not deploy the piston. Reservoir full but with very dark fluid. My strong suspicion what is causing the failure is the high temp from long tube headers that were installed. There is only about 2 inches separating the slave cylinder from the header. I am thinking of making a heat shield to separate the two or heat wrapping the header or both. What have fellow members done & do you have any pics of your heat shield?