I Have two sets of crowers, both sets were in the block this week for test fit no issues, as for using parts you already have, everyone wants too, I just sold a set of BME rods with 10-15 passes on them for 1/2 price when I bought a new block, because I needed another .010
These are custom built Motors not some stock rebuild that means custom parts if you want to order parts that slip in and come from JC Penneys build a chevy!