Well guys this is how bearing life has been for me , I seem to get about 12 gallons of fuel through the stock rear bearings and then replace them with TKO ceramics ,the fronts all the stock ones only lasted maybe a gallon before the engine started to act up , I changed them out for Double Sealed bearings
and have never looked back PERIOD !!! You can leave the second seal on them , just get high temp high speed bearings , I forget the specs as it has been 3 years since I have changed them !! What I do know is they are made in England and have brown colored seals . They work PERFECT! As for the rear bearings all my engines take the 14mmx 25.4 bearings ,as of right now I don't have any with ceramics in them ,but that is about to end asI am going to put ceramics in my 421B for next season.
