well since we were NOT there to hear the noise, its rather impossible to know what your problem is, based on you saying you heard a knocking sound>
it could be a LOT of things
where is the knocking noise coming from, location,
diff, front or rear, motor, top or bottom,
and I also think its pretty impossible to bore to a 670 in a 400, but guess anything is possible??
but if you went that far over stock, odds are the motor isn't going to last very long, and be rather weakened from all that boring that happened!
it could be a LOT of things
where is the knocking noise coming from, location,
diff, front or rear, motor, top or bottom,
and I also think its pretty impossible to bore to a 670 in a 400, but guess anything is possible??
but if you went that far over stock, odds are the motor isn't going to last very long, and be rather weakened from all that boring that happened!