Update:
After cleaning my block, the machinest found a couple cracks in the lifter valley. He reccomended I find another block. Yesterday I picked up another engine off Craigslist. It is the same casting number as my original,14093638 and cast for the roller lifters, but the final machining is not done. I think I can handle drilling and tapping the spider risers and camshaft front retainer plate mounting.
I mocked up a dogbone and lifter and found there was quite a loose clearance where the lifter fits inside the dogbone. So much that even if the dogbone doesn't sit perfectly square with the lifter, it still slides up and down without resistance. At this point I'm thinking of just grinding a little off the backside bottom of each dogbone where the the block is filleted and it should sit and operate just fine.
If anyone has any personal experience with this, I would appreciate their feedback.
Here's a couple shots of the new block:
http://i395.photobucket.com/albums/p...d/DSCN1287.jpg
http://i395.photobucket.com/albums/p...d/DSCN1292.jpg
This new block is not drilled for the mechanical fuel pump either. I'm a little disappointed as my cracked block was almost perfect for what I wanted. I understand there is a jig out there that can be purchased for drilling for the the pushrod and drain hole, but it cost almost $1000. That's ok, I've run electric fuel pumps before and do not object to them at all.
http://i395.photobucket.com/albums/p...d/DSCN1290.jpg