240 to 390 swap transmission questions....

[sizemoremk]

I just realized I placed this question in the engine forum by mistake, sorry for the confusion.

But here goes.

I have a 240 inline six with a manual 3 speed column shift in a 73 F100.

I am conteplating a 390 swap, and would like to know if I can keep my own transmission. For the time being anyways...

I know the bellhousing, flywheel, clutch, etc will have to be swapped, but I am hearing confilcting information elsewhere on the web concerning the input shaft lengths being different, and was hoping someone here could help me. Some say it is the same, and others say it is different.

I know this is not a 73 truck board, but I am hoping that you guys will help me out ayways...

Thanks!

[cobraF100]

Sorry but I deleted the other "same Post" that was in the Engine area.So this is the only Post now...


Wish I could help you on the on this swap but I don't know enough to make a statement that mite give you the wrong info..

['75-4x4guy]

I think the input shafts are the same with all of the 3 speed truck trannys .
I dont think you will have any problem .
The 240 engine to chassis mounts will work on the 390 but you will have to move them back into the other pre-drilled holes .
other then that it should be all bolt in !

[flyboy2610]

By the way, welcome to the site!
Stop by the welcome mat forum and tell us about yourself and you're truck.
Where do you live? I'm goping to pull the 390 and tranny out of my truck within the next 3 weeks, and I plan on going to an automatic. It has a T-18 4 speed in it now, it's a top loader tranny with granny gear low.
If you live anywhere near Lincoln, Ne you can come get it for free.

[truckjunky87]

You will also need to keep in mind the clutch rod pivot on the engine side is different between the two and throttle linkage will change. I just finished swapping a 240 with a 352FE but my transmission was the np435.

[Docholiday72tx]

I'm pretty sure I have that throttle linkage for a 390. You can have it for shipping if you need it.
Doc

[willowbilly3]

I put a 390 in a 6 banger truck and just made a throttle linkage from some small cable and a couple appropriate sized cable clamps. The truck is still in the family and it has been working fine for over 20 years now.