I have a 1967 340 block I got from a friend of mine that has them installed. I am not crazy about the angled bolts, and where they go into the block. Not a lot of surface for the bolts, and can only drill and tap a minimum depth. I didn't see it necessary for this application, but they are on now. Unless you are missing some main caps, I don't think I would do it. I think the better option is the Mopar Performance caps that Rocket has for sale . I am reassembling the engine now. It has a set of W-2 heads on that leaked, so it had very little run time and never raced. So the main and rod bearings looked fine. But I can't testify if it will last yet.
