CHEAPest way to convert rear axle bolt pattern to big bolt pattern???

#1 or#2 gets my vote. If the flanges were larger and there wasn't the big hole for a socket to go through so you could unbolt the axle it would be a lot simpler. If you want to keep the rear end, I would get new axles. You have already spent some dollars for the front. Spend a few more and get it done right. tmm