What you really need to do is send the block and crank off to the machine shop. They will be your best bet on telling what you need, They could also offer to balance your assembly for an additonal 200.00, usually the going rate. However, you might be stepping into a whole new world, it might need a bore, and then when you bore it, you will hot tank it, then might as well get it demagged, line and plate honed, and all the goodies, then 500.00 later, only on the block, then you will need new slugs. It just depends. If you plan to go low dollar, like what you seem to be pointing at, just a rering, and new bearings, take your old ones out and measure, but personally, I would have the crank checked by a good shop. Have them polish it and chamfer the oil passages. And they will tell you waht bearings you need.