[blykins]

Yes they will.

The later model lifters only work with the lifter spider. If you drill and tap the early block for the spider, then it has to use the late model roller lifters. The lifters are the same diameter for both early and late blocks.

Your other option is to skip the spider and use a set of link bar hydraulic roller lifters. You can usually find good deals on link bar lifters....I think if it were me, I'd skip the drilling and tapping on an assembled short block and just throw the linked lifters in there.