If you have a rod bearing knock then the crank journal for the rod and the connecting rod itself are damaged. You will need to have the crankshaft reground and refurbish the connecting rod. Typically this means they will grind .010 to .020" off the crankshaft journals and cut the connecting rod and conn. rod cap then rebore the hole to factory size. Then you'll use undersize bearings for both main and rod bearings. Most machine shops will charge about 100 to 150 to regrind a 4 cyl. crankshaft. In an over rpm situation, probably be a good idea to refurb all of the connecting rods and get all new bolts/nuts for them as well. You never know if any other bolts have stretched. I thought I saw someone post a link to a shop that sold complete rebuilt longblocks for like 5-600 bucks...that may be the cheapest way to go.