Actually ,you have the cam,heads,and more to lose. Swap it Now.( Drop wrench )Hmmm. I know mine is externally balanced. I was feeling pretty good until you said that part! I wish I wasn’t right in the block splitting level. With as little as I drive the car, I feel like I’d be fine with a good tune. However, that’s why I asked for the opinions of everyone. I guess I don’t dont have much to lose if I freshen up the stock block combo and it fails down the road. Swap it over now or wait and swap it when I’m forced to.