A 1977 Ford F-250 would have had a 302, 351M, 400 or 460 engine. More likely the 351M or 400, but could be a 460. Maybe post a photo and I may be able to tell you........Check out the link.....https://en.wikipedia.org/wiki/Ford_F-Series_sixth_generation
Can I put a 5.4 V8 into a Ford f250
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