1979 Ford Racnhero - 351W or 351M?
 

I can't figure out what kind of engine is in my 1979 ranchero. The VIN indicates it's a 351W, but the sticker on the side of the valve cover says it's a 351M. It sure looks stock (like it has 30 years worth of grime on it). The guy I bought it from was a mechanic at a Ford dealership for 40 years and told me it was a modified. It's got all the smog equipment on it. I've read some things about an "obvious fin" near the distributor of the 351W, but I don't see that on mine, or I misunderstand what "obvious" means. Everything except the VIN seems to indicate it's a 351M.

Does it sound like the engine was transplanted from another vehicle?

Also, since it's possible the engine isn't original, according to the sticker my car originally came with the FMX transmission, but I'd like to verify that too. How can I tell what kind of tranny I have?

Thanks a lot in advance.

-Richard

RE: 1979 Ford Racnhero - 351W or 351M?
 

Tranny. can be verified by the number of bolts and shape of the transmission oil pan. FMX is more rare. Maybe why they changed it out. 351M is a modified Cleveland big block. 351W is the biggest small block and resembles a 302 or 289 greatly and many (not all) parts interchange. A picture would likely bring fifty 100 percent Identification of the motor.

Here this PDF will ANSWER all your questions.

http://www.delray.com.ar/dt/junkyard_guide.pdf

Easiest way is to look at how the thermostat housing is mounted on the engine. The Windsor bolts to the front of the block and the Cleveland/Modifieds bolt to the top of the block.