Starting planning a cummins swap on my 03 f150 5.4 just looking for some info and tips. Wondering if a 4r100 from a 7.3 would fit with little modifications. How will the 4x4 drive line hold up? Options on suspention upgrading. Oil cooler trans cooler and rap upgradeing? Intercoolers from ford diesels ? And any other info that could be useful

 

Or a 5r110

 

An 03 F150 is not heavy duty enough for a cummins especially if you want to use it for towing or just using all of the torque. The brakes suck for one thing. The F250s have bigger brakes, differentials, axles, bearings, better cooling, on and on.

 

It has already been done on one of these forums.
It's a lot of work because everything has to be changed.
You can't put a different motor against the Ford trans.
It's just not worth the effort and expense unless you have special application and sure you need to do it or your 'bull' headed.
A well equipped shop, time and money are the needs for the project.
Cutting Torch, welder, metal stock, time, tools and money.
Good luck.

 

lots of time tools and $$money$$

 

It can be done. I've done my self, actually im not quite done the build. I'm using the Cummins 4BT and turning the wick up a good bit. The 4R70W might work with a stock 4BT, but I wouldn't bother; just go ahead and use a 4r100. I don't know if a Diesel version will fit but i'm gonna use the lightning version. I already blew a 4r70. But in the end its still a ford truck & i'm not a ford fan (I did the swap for a buddy). If you plan to go ahead and do the swap keep us posted and i will try to help as much as i can. Good luck!