I have recently noticed blue smoke from the exhaust,usally at higher rpms when you let off the gas.no smoke is present at startup or under normal driving.The motor is freshly rebuilt 10k ago w/ new sportsman heads.the motor holds 15" of vacuum with the moderate cam it has.So could it be a intake manifold gasket leak,bad valve seals or guides? I was told that intake leaks can be problematic,one person reccommend using silicone on the intake ports too eliminate leaks,seems too me that gasoline would eat the silicone? Anyone have any suggestions TIA Joe

 

blue smoke usually indicates an oil leak, i have never had to silicon the intake runners, and i do believe solicon and gas dont mix, if the motor is new, i may still be breaking in, though you did say it was 10K old.. maybe some crap parts to a dump