I found the numbers I think but it doesn't make sense if the smallest GMC size is a 228 plus they both appear to be on the drivers side so they are not on the same side as the distributor. The two SNs are 2136477 with a AY under it. Also on is a "A3 1". On the other engine is 2194819 with a B under it and "F9 3". GMC is stamped onto both of them
