docfe Doc why not stay with the bore you have and go with a stroker kit? 4.25 with BBC rods. If you want to bore out the block that big, have it sonic tested first. Some guys on this forum have lost blocks to this procedure not being done first. The other issue is where did you get the block from? Was it a pump motor? boat motor? U-haul? Sonic first before any boring.
. After boring build yourself a nice stroker. Rick L.