The smaller bearings produce a slightly less amount of heat. With the stroker cranks it makes the desicion even harder. I would look for a short cut to make the decision easier. Like if you could find a project engine that wasn't assembled but all the parts were bought. Not a box of rocks. Something with receipts and great parts. I saw a nice 455, new and ripe for the pickings that could have been bought for $3500. I would leave my mind open and look for deals. Sounds like you have a 'clean slate' to start with.