I've saved some pretty bad bores before. Get a properly sized dingleberry hone and some P'Blaster and hone the hell out of the cylinders. It might clean up. A true performance engine is generally a little looser anyway. I've run a forged piston 340 with almost .010" piston to wall clearance. LOL It ran quite good too. I used file fit rings and got the gaps right. Even still of course, it wasn't for the long term, but it did run good. And yes, it had piston slap. lol