If they charge 6000 bucks more to take the block out an extra .030 during a fresh build, there's probably more to their 434 package than just the bore job. For the life of me, I cant imagine what though. So, if Shafiroff is going to do the work you want, I can only imagine it would be more than 6000 to do on an existing build,I never knew it was so easy to build a 434sbc from a 427sbc that's why
I originally wanted to have Shafiroff build me a 434sbc but that would have been $6k more than I wanted to spend at the time
The closest track from my location is Beech Bend raceway park in Bowling Green Kentucky and that's about 60 miles from my location . The over one hour drive would be not fun at a 3800rpm cruise rpm
The two years the 427sbc has been in my Camaro I've only driven maybe just under 600 miles
Right now you have an awesome, leak free big inch motor with an iconic displacement, no ring seal issues or tuning problems.i would hate to go through all of that and end up with an issue.