Hi,

I'm still contemplating possible avenues for my project truck, and was wondering how much difference there is in mpg between a 4 door crew cab and a regular cab truck. How much weight difference is there? (300-400 lbs?) and what could I expect for gas mileage if I take out the 6.9L diesel that currently gets about 17 mpg (but probably has some pretty extensive engine damage) and replace it with a gas motor (I have a 400, or thinking about a 351w...). My truck is a F350 4x4 4 sp manual, but I'm interested in hearing from anyone who drives a crew-cab and what their mpg and drive train is. Thanks!

 

The truck really won't weigh much more than you have figured, about 400 pounds tops. These older trucks don't have all the gizmos and sound deadening that the new ones do to weigh them down.

If you are gonna do an engine swap, I would not waste my time going to a small block. I wouldn't bother with the 400 either unless you have experience or somebody very knowledgeable with how to make power from one. If you wanna keep mileage up and get good power the only thing I would recommend is going to a 7.3, preferably the '94 and up PSD version. The IDI turbo models have really high compression and don't allow a lot of modification. If you want power but are ok with 10 mpg, I would recommend a 429 or 460, but remember your bellhousing is diesel only so a new transmission will be needed as well. A small block wont get better mpg than a diesel in a pickup of any size, and is a downgrade imo.

 

Stay with the diesel you'll get better mileage. I would kill to get double digits outa my F350 with a 351W and 4x4