I've played a lot with a couple older molds that cast 4-1/32 and 4-1/16 and was able to get a #2 hook in the 1/32 cavities if I left every other cavity empty...casting just two at a time. I was also able to cast the 1/32 as small as a #8 but had a little flash. I could cast the #8 in the 1/16 but then the leg length kept the line eye darned close to the head and the flash was borderline bad. I was able to get a #1 hook in the 1/16 too, but had to settle for a 2 head cast.
There are a lot of possibilities with the molds, but the biggest challenge is the leg length from the shank to the line eye. In the case of over-sizing the hooks, the leg can be too long. In undersizing the leg can be short enough to be a problem, casting very, very close to the head. I was able to do some minor mods to the mold mentioned, not in the cavities proper, but where the shank run into the mold body behind the head, that involved removing a slight amount of material so the hooks could be cocked yet with the eye in the proper spot. This was done for both larger and smaller than the standard hook sizes.
Playing with out-sized hooks can really change your fishing though and I endorse it whole-heartedly.
The Eagle Claw Sickles b.eipert mentions in his post are some ideal hooks. The leg length consistency is flat out outstanding in this line of sickle hook. That goes a super long way in how well the outcome of these mods come out.
