Sorry that I haven't posted back with the numbers before now, but here they are. I had a GM 19 and a 388520. I believe that the second number is right, but if there is anything that you can notice that wouldn't be right, I would be glad to recheck it. Hope this is what your looking for. By the way, I posted this also in the Chevrolet forum(which I haven't gotten much response or help) and one guy told me to use it as a boat anchor...Then he told me that I need a 350 or 400ci! He thinks I could afford that, is he crazy? My goal for this engine is to get it just as fast as a 350, but still have the 307 block. I doubt I will make it to that goal, but it's worth a shot. Thanks again for your help!