I just purchased a 1980 f350 custom 2wd 400 with a 4 speed. It was used to haul draft horses all its life and only has 65000 miles. My question is can I take the 400 out of this truck as is, in stock form, emissions and all, and be able to put it in my 1979 snowfighter in place of its 351m? I can see the emissions are a different set up but I'm wonder how different? To me it looks like I could pull the motor out of my 79 and put this one in its place as is. I even think the the oil pans are the same.

 

I don't see why not ... motor mounts will be the same. Bell housing pattern will be the same. Etc. If the '80 has cats and the '79 doesn't, you'd need to swap some exhaust over in addition to the engine. If both do or both don't, then I would think everything else should work fine.

 

I've been doing searches on the web for information I can find as well. I read something about the M Block using a sort of sensor by the catalytic the run the emissions on the 80 and newer.

 

Ford used feedback carburetors on some engines - these would have an ECU and an O2 sensor in the exhaust for feedback, and the thermactor air system would pump the air in at the cats rather than the exhaust ports. I don't know if they ever did it on the 400 or not, but even if so, you said you would take it "emissions and all" ... that's just part of what you'd swap.

You already have the truck, you said ... go look and see what it's got in it. Is there an O2 sensor? Is it a feedback carburetor or a straight mechanical one?