Truck engine vs car engine
 

I know this has been answered before but I can't find it. I understand that the basic difference between a car and truck engine is the cam. What is the difference and which is better for mileage with an AOD and 3.55 diff. I currently have a car 5.0 in my 90F150, is it worth the bother to change the cam? I also have a low mileage 351W that I am cinsidering swapping in but have no idea what cam is in it. It is an F0AE block. I do very little towing.

If you are satisfied with the way it runs, leave it alone. Usually, "truck cams" focus on off-idle and low rev power, and sign off after 4000 rpm or so, some earlier.

Mileage wouldn't be drastically changed.

What car engine are you talking here, the passenger car 5.0 or the Mustang 5.0?

Unless it's the Mustang HO motor then yes... absolutely.

A stock 5.8 of this vintage would burn more gas but not deliver a lot more power, but upgrade the cam and it would be a FAR better truck motor than any 5.0.. regardless what cam it has. It will be a little harder on gas than the 5.0 around town but better on the highway simply because it won't downshift on anything but really big hills.

Yeah, since you already have a 351w... if you are thinking of upgrading the cam because you want some more downlow torque, or more power to pull trailers... go ahead and bypass upgrading your cam and just swap in the 351w.