Chet-- I am showing different part numbers between the two years with the housing and block (Master Parts Catalog). The thing is, the New Finer Plymouth was introduced in mid 1930. So, were the earlier 1930 parts the same as the '29s? The PA had a 196 cid (I think), our's the 175 cid. The manual shows no serial number cut-off for the U block which is strange, I wouldnt chance it unless you can tell the spare is a 175. Personally, I would pass on it.