Things seem so much smoother when a 350 motor doesn't have a 454 flywheel on it. Some previous owner down the owner chain decided to use a 454 flywheel on this 350. I wonder how long the bearings will last now. I didn't drive it much like this, but who knows how long it was run before. Only 5 bolts out of 6 were holding the bellhousing to the motor. The bellhousing was cracked. Some of the bolts were hand tight. The clutch disc was cracked in two spots. A starter bolt was broke off in the block. The little clips that hold the throwout bearing on the clutch fork were broke off. But it's all fixed now and runs smooth. I had a SB400 once in a truck I bought that had the wrong flexplate. I swapped the motor into another rig with the proper flywheel, but after a couple months, what was left of the bearings wore down and it started knocking. Anyone else have balancing experiences? How long would you say it would take being run out of balance to permanently damage bearings?