I agree I am putting one together now and I had backed off on going .030 over for that reason, to keep it around a while. I measured taper and figured my rings will seal, and for the mileage ill put on it it should last as long as I have it and it is the numbers matching block to my car. the 340 in the car is period correct but not numbers matching and that one is .30 over. But yes i would think as a race motor I'd build something "more affordable"