In Reply to: timing gear cover question? posted by chris eby on October 21, 2018 at 09:07:23:
If was to speculate, I'd say cast iron came first. MPC's show 9N-6017 only so that means no change made to it ever. The SEP 52 MPC shows the 8N-6017-B version, aluminum alloy.... I will have to look at both my early '39 9N and my early '48 8N tractors to confirm. Also this MPC shows 9n-6019-B, but no material spec. It does show 8N-6019-B as aluminum alloy. The "B" suffix would indicate at least two versions were made. the March, 1940 MPC lists p/n's 9N-6017 and 9N-6019-B as does all the rest of the 9N and 2N MPC's. I'm headed to farm today so will check mine and get back.