Hello fella's I have run into a bit of a problem while rebuilding my 99f150,So to begin the tranny and engine were toast in the pick up.So I bought a believed to be 98 f250 engine and tranny,umm then engine is the exact same (5.4triton) but the transmission were worried will not fit because of the rear crossmember.

The old transmission part# is RF-F7AP-7006-AA
and the new one i want to put in is: RFF75P-7006-ad

any help that you can provide or suggest would be much appriciated, And if you guys have ever done a swap out like this please advise me on what to do.thank you

 

Your 99 has a 4r70 trany and the F-250 has a 4r100.
In order to put the bigger tranny in you will need some parts.
You need a cross member from a truck with the 4r100 ,dipstick and tube from a 4r100 ,tranny wirer harness for 4r100 + a computer to run the 4r100.
That's most of it for a 2WD truck. If you have a 4X4.You will need other parts also.
I think you need the longer torsion bars from an F-250 in order to fit the T-case in there.
You will also need drive-shaft adjustments on your back drive-shaft and the front one.

Phil

 

In other words he is telling you that you are going to need to replace the computer, rewire the truck for that and then have to get a tune to take care of any minor issues and the one big issue called PATS.

Not a job that I would take on. All pain and very little gain.

Darrin

 

Yeah,
I forgot to mention the PATS.

Phil

 

Alright thanks, so in other words lets just rebuild my tranny eh haha, umm is the 3/4 ton tranny better in any way ? just wondering if it would be worth it at all? cuz we have the techonoligy to do it,I myself dont want to **** with the computer cuz everytime I hear of someone doing that its an endless battle.

 

Alright thanks, so in other words lets just rebuild my tranny eh haha, umm is the 3/4 ton tranny better in any way ? just wondering if it would be worth it at all? cuz we have the techonoligy to do it,I myself dont want to **** with the computer cuz everytime I hear of someone doing that its an endless battle.

 

Buy the time you buy all the extra parts and have the new computer tuned to turn off the PATS.You could probably just have the 4r70 rebuilt.
The bigger 4r100 is stronger but theres really no benefit unless your making over 500rwhp.

Phil

 

just have your 4r70 rebuilt

 

Okay thanks mate for the help,Ill be rebuliding it soon

 

Wr are having the exact same issue you had. How did it go for you? Need answer asap!

 

It's been 7 years since the last post, but by some miracle he might answer you, but I wouldn't hold my breath.