Replaced intake and and drove

I do not have a year or motor size so I am going to guess 1990 350 V-8. Here could be a reason for a knocking motor. In order to replace your intake you had to pull your distributor. The shaft on the bottom of the distributor fits into a forked type shaft that is connected by a nylon sleeve and It turns the oil pump. All this is turned by the gearing on the distributor. If you did not stab the fork when you where installing the distributor or broke the nylon sleeve that fits to the oil pump then you were not turning the oil pump and this would cause your motor to not lubricate itself. To do a quick check remove one of your valve covers and turn you vehicle on and see if oil is squirting out of the rocker arm holes. This will tell you very fast if you are getting oil throughout the motor. Good luck and I hope for the best.
Dreamweaver1