can some please tell me the difference betwee the 351m and the 400?


Asked by Oct 11, 2012 at 04:51 AM about the 1973 Ford F-250

Question type: Maintenance & Repair

just would like to know what really uder the hood of my 73 f 250

2 Answers


OK here's the skinny on Ford engines. Pay attention because it gets confusing. LOL !!! The 1970's were a milestone for Ford and many changes took place in the cars and in the trucks in those years. The 351-C, the 351-M and the 400-M were all the same block but were quite different externally and very little items interchanged between them. Now since you say you have a 1973 F-250. If it's the original engine, I would go ahead and say that you would have the 400 in it as the 351 -M didn't come out until 1975 when Ford discontinued the 351-Cleveland at the end of the 1974 model year and as far as I can remember the 351-C wasn't available in trucks at all. They did however offer a 360 in the F-series trucks from 1974 up thru 1977. The 360 was a completely different block. It was an FE block (FE=Ford/Edsel) and was identical to the famous 390 engine which was also in cars and trucks up to early 1971. Most of the F-250's had the FE 360 engines in them after 1973. Most of the F-100 and F-150's had the small block 302 or the 400 up to 1974 and either the 302, 351-M, the 400 or the 460 after that. The 400 came out in 1972 replacing the FE 390 engine in cars. The 360 replaced the 390 in trucks. .Ford also had a 429 engine as an option up to 1974 and that was replaced by a 460 (same block as a 429) from 1974 and up in all the fullsize cars and F-series pickup trucks. So you have to have either the 400-M engine or the 360 FE engine. The Fe engines intake manifold ran under the valve covers by about 2 inches, the 400 engine did not as the intake was mounted inside of the valve covers. Ford also made a 351-Windsor but it was basically a 302 block and had unique looking valve covers that had a "V" effect when you looked straight at them. Kenny/MrBlueOval.

3 of 3 people found this helpful.

thanks u very much i do have the 400m but the there was a 360 in the to start a owner changed the motor out to an 80s 400m, i ran the vin number on the truck and it told i came with a 360 and when i went in for a locker i have the ford team run my engine ser # and it came out of a 150 form the 80 witch is fun because befor this truck i had an 81 f150 with the same block

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