I've waited over a year for the Milodon ductile iron 4 bolt main cap setup. Now pushed to June. I'm looking for a new path forward for an oem iron block 440RB block stroker.

Can I use aluminum main caps (I've read the advantages from search past posts on main caps) without having to take the motor out and tear it down regularly? Or can I use billet steel main caps perhaps with a girdle (not looking to use BCR as don't want to have to consider shimming motor mounts, extending pickup, etc) with a steel rod 508" stroker with ~600 HP? From my reading I'd go with ductile iron main caps if I could find any new. And have been advised to use billet steel versus aluminum to not have to service motor/bearings regularly. I've got 99% of parts and ready to get to a machine shop... Thanks.