An experienced racer told me once that it was a good idea to drill and tap the block. I wish I remembered the size of the tap, I have it at home so Ill have to check back in. Anyway, the tap wasnt much bigger than what the 1200's used. He drilled and tapped the motor so its threaded all the way through both halves of the block to the bottom side of the motor. He then bought longer bolts so it threads all the way down through. I bought a motor off him that had this done. I also have an 1100 motor that I partialy did this too.. The bolts dont go through both halves but they are much longer then what many use. Even though I check em every week, this still helps reduce the chance of them backing out.
If you do this, buy and extra long drill bit. When tapping the block I was able to use a ratchet and extention for clearance, just be extremly carful, little turns at a time, you dont want to mess this up.
Eric
