Holley 1920 missing parts - time to swap?

I am not an expert, but if they make two different weight floats, it is for a reason.....It is not the float level that matters as I think they are both 3/16 from the top of the casting....It is a weight issue....buoyancy issue.....I would think the float spring is heavier on the 12.5 gram.....If you would change that to one that is correct for a 12.5 gram float it may work....