about the only diesels you could transplant into an F150 would be the cummins 4bt, 6bt(maybe) or a vw diesel(sucks) also the front independent suspension wouldn't support the weight of a diesel engine either. before any one gets wild ideas about a powerstroke of any variety fitting let me stop that one...will not fit. the powerstrokes are much to wide for the f150's engine bay and you'd need to do extensive body mod's to make it work, but it would be sick to have a 6.0 in there. plus its just way too expensive. Ford needs to build a diesel 1/2 ton but i don't believe they ever will, even though it could achieve 25+ mpgs