theres SUs, which were made in the 30s, these were crap and where "SUs" get there bad reputation, but the datsun versions are actually hitachis which are a copy of the basic design of the SU's and hence are called SUs, but actually they are not SUs

confused yet???

but anyway the datsun versions are a great carby, most people turn up there nose at the mention of SU's but this is due to the early versions, which true to what people say were crap