Trying to determine size of existing Blower and not sure how to interpret the only numbers I can find. The the top surface of the back I founf "10 s 12"? Anyone explain this?

Oh ya, they are Littlefield's!

Scott put up a pic on the motor with the distributor ,will make it easier

Measure the case, just the solid middle section not the entire blower. some of these are rounded up but should be good enough for you to figure out whatcha got..

671 = 15", 871 = 16", 1071 = 17", 1271 = 18", 1471 = 19"

See pictures. It does measure 19"???

Is the concensus that these are 1471's?