I just finished rebuilding my motor, I opted to use the block that was in my car instead of using the one that I have laying in my garage, took it apart, 2-bolt mains, but used it anyway, bored .030 over, shot peened rods, 10.65:1 compression hypereutectec pistons, edelblock 6085 ported heads, put it back in and yesterday started stripping the other motor just in time to find out that it is a 4-bolt main , needless to say, I am going to start building the 4-bolt pretty soon, but I was pretty pissed off at myself for not checking out the other block !!!
-I will post some pics of the spun bearing and others in a little bit

-Gabe

 

2 bolt mains are good for an awful lot of power (I think between 500 and 600 HP). I wouldn't worry too much about it unless you are going with a blower to complement the 383 build.