I have two or three of those FT setups with the iron crank/small snout. The two I took apart were 330MD, and had small snout iron cranks. I think that was where they were used like that. Never saw a 361/391 with an iron crank. There were three cooling setups in heavy trucks. The "normal" FE type timng cover with a big seal hole, the one in Chris' pics, and the heavy duty cooling with the big seal hole for the steel cranks. I used to sell parts to CSX and Norfolk Southern for all three ideas. Some HD stuff even had dual thermostats just in case one failed..... they had a big square cast box that held the two thermostats. Okay, I'm off track now, but they really made some SUPER DUTY FT stuff way before Ford recoined the logo in the late 90's.