Hey all, I'm building the block of my 83 B23F. It already has a rebuilt stock 398 head with VX cam advanced 2.5 degrees. With this and an M46 my 245 is fun, so much fun that I trashed my piston rings five months post head build. I'm aiming to get a little more power from the engine in a minimally invasive way. Porting is too much $$ for me right now - I want to know how much I can skim off the head and/or block without affecting cam timing or causing detonation. No tight squish here. I also intend for the engine to last a few hundred thousand miles while being driven fairly hard and passing emissions on 89/91. I know these engines get their reputation for durability because they're understressed from the factory, I want to know how much I can push it without significantly sacrificing this. Injection and ignition will remain stock, and m46 untouched with 415k.