I really want a diesel in my truck. Ive been on the fence for awhile now and I cant decide which engine to go with. Currently I have a 92 f150 xlt with a 4.9l and e40d. Ive been debating between a 7.3l or 4bt, but im having a really hard time deciding because they both have advantages and disadvantages. My plans for the trudk is to be a daily driver with a 4in lift and 33s. I dont plan on towing anything big like a 5th wheel but i will be towing a boat 20 or 30 miles. Here are the pros and cons of each engine the way i see it.

7.3l: pros
-direct swap
-easy to find parts
-just need a donor truck
-can find everywhere

Cons:
-heavy
-ok mpg (14-16 city, 18-20 hwy)


4bt: pros
-great mpg
-lighter than the 7.3l
-more tq than the 7.3l
-low maintenance

Cons:
-hard to find parts
-more expensive parts
-everything will be pieced together


not trying to start anything I just would like some help, plus if i missed anything please let me know.

 

The suspension wont handle a 7.3

 

Well i figured with either one i would have to do something with the suspension

 

Ok, as long as you know this. Personally I would do a 7.3

 

Im leaning more towards 7.3 swap just for the fact that theres no guess work. What is a good way to beef up the suspension?

 

although there will always be people who know about suspensions, here's a little piece of thought..... no matter how cool a set of springs and shocks turns out, ultimately the weight is carried on the wheel bearings, spindles, etc right there where the wheel-flange meets the brake disc, and if stuff is really heavy, those pieces will wear, heat, distort and fail much more quickly than they would have under stock-weight stuff.

You'll get away with heavy-assed stuff riding on a 1/2-ton axle set for a while, but, eventually, you're likely to be that poor bastard on the side of the road with a wheel that really looks weird because it broke off an sits crooked under the fenderwell.

get some 3/4T components and drive around with happy confidence

 

The more I look into diesel conversions the more I shy away from the 4bt and lean more towards a 6bt or 7.3l swap. The reason being is there are tons of 7.3l and 6bt running around in my area so I know finding parts for either one will be easy. Not being able to find parts is my greatest fear with a 4bt swap. Yes i know I can use parts of a 6bt but not all of them...right?

 

I'm not an engineer, and I don't play one on TV, so the real Diesel guys can explain it better than me, but, the 4bt lacks "internal balancing", so needs more creativity on flywheels and harmonic balancers. Otherwise, the shaking will wreck the rest of your vehicle. I suspect that's why so many bread/chip trucks are in the salvage yards with very-good-condition 4bt's in'em. Why else discard the whole damn vehicle? 6bt shakes like hell, too, but, it's a nicer kind of shake, apparently. .....but if you've got a good Diesel shop in your geographic area, parts and repairs for a 4bt ought not be a point of run-and-hide.... just that shaking, and its 700lb beefiness

 

Ford put the 6.9/7.3L in D44TTB trucks (std. cab F250) up to '91. So based on that, draw your own conclusions on how heavy-duty your front axle needs to be.

If it were my project, I would be looking at a IDI/5spd combo, add a turbo, and 05+ Superduty axles. They're certainly beefy enough and front already setup for coil springs.

 

Its still hard deciding between either swap. One thing that has been puzzling me is how are cummins swaps cheaper than a 7.3l swap? From what ive seen 4bt/6bt swaps run about 5-10k and for a 7.3l swap you just need a donor truck which runs 5k or under.