Is anybody using the Spectro 85W Primary Oil? I'm switching over to their 6 speed oil in the transmission and wanted to keep it 'all in the family' so to speak.

 

I am using the spectro primary oil. I have used their engine oil in the past and liked it. Seems to work fine, the mobil 1 worked fine, and the HD stuff also worked fine. So not sure which is best, but IMO, any of these are GTG

 

Your fine with almost anything in the primary but you should stay away from synthetics if your motor is built or you will have clutch slippage. Running ATF is not the best lube for the compensator, causes fretting. I use and recomend Harleys Formula + for your primary