I know I'm opening a can of worms here, but please chime in. I had planned on rebuilding the 350 in my 79 Z as the previous owner had it all screwed up. The block ended up being a 2 bolt main, and my spare thats been sitting in the corner is also a 2 bolt, which has me rethinking my 480-500 HP 383 that's been spinning in the back of my mind. It will spend 80% of its time as a general cruiser, but will see the strip on occasion. I've had 2 bolts converted to splayed 4 bolts on my race only motors in the past, but the street is kind of new territory for me. With all the other work the car and drive train needs, I really don't want to spend the extra $$ to splay the mains if I don't have to. The floor is now open guys.