You don't need to pull the balancer hub off to change the Opti, just pull the balancer/pully itself off. One other note on the LT1 balancer hub. It is not keyed like a normal SBC balancer is, it is just pressed on. You can't manually adjust the timing like on the old SBC due to once the relationship between the crank and cam is established via the timing chain, your timing is set. The Opti has a drive pin on it that indexes the timing off the camshaft. The computer does the rest. Are you gonna put a new seal for the Opti in the timing cover? Make sure before you install the Opti that the teflon seal and the Opti seal running surface are super clean. The teflon seals don't like any lube when installed, if there is they will leak.


Keith