RE: Blue Star Models Hetzer Resin Kit
Kevin, I think a set of the Type 3 Tammys will fit. They are lower than the Type 1's you tried, length is about the same. If there is an interference problem with the upper hull front plate, with a little ingenuity one can trim here and there on the transmission frames. For an output shaft, you can used the stockers or if you want a straight shaft you can use a Pershing output shaft and if needs be the Type 1 sprocket adapter.
I do not have a set of the Tammy P4 TU's here, but if memory serves they are lower still than the Type 3's that go in most everything else.