Stroking the crankshaft to some most 81mm will retain the RPM functionality intact. Bores can be introduced out to 83mm, but try to maintain it under 82.5mm. There is absolutely no have to have with the System Atlantic crankshaft. Reject blocks which will need to have 83mm to scrub up, https://4a-ge-engine-for-sale50369.ttblogs.com/6225817/rumored-buzz-on-4a-ge-engine-for-sale