Those rings are what is referred to as "drop in rings", fitting them is not required. However, they should be checked. Also, on file fit rings, the spec that is given is the MINIMUM amount of gap required, with more gap being "acceptable", to a point. A while back I was building a basically stock 390 ford and the drop in rings measured about .048". I called the ring mfg and was told that up to .055" would be ok.

Brian