I have a 1975 F-250 High Boy 4X4. It currently has a very strong running 360 FE in it, however, I've been toying with the idea of a diesel swap. I felt an IDI may be a possibility by virtue of their availability, relatively cheap price and simplicity compared to more modern diesel engines.
That said, I REALLY like my cast iron, granny geared (6.69 1st gear) NP435 tranny, soooooo, anyone know if an IDI will bolt to my NP435, OR, if anyone makes an adapter for such a conversion ? Thanks.

The question is more will a bell housing from an IDI bolt to the NP435, as FE uses a bell specific to only FE motors, and the same for IDI's. The only factory 4 speed used behind an IDI is the T19. I seem to recall having heard others using the T19 bell on the 435, but I cannot validate that at this time.

Ok, with a little checking, the diesel bell will bolt to the 435, but the problem is with the ratio spread not working very well with the diesel.

Whys that?

Max rev on the IDI is around 3500, they don't like to be spun real fast, like any diesel. Gas engines can have a wider spread between gears, as they don't mind spinning up more. Diesel engines tend to do better with close ratios. They are all about torque down low.

Ah yeah come to think of it 435s do have a pretty tall 3rd gear. Thats really the only problem I could see with it. 2nd and 4th are ok. If ya want a close ratio ya could do a muncie if theres any way to adapt it.

Be just as far ahead to use a T19 that is already set up for the diesels, plenty of them available. Could go even as far as to do a ZF swap.... If you are looking for strength, a T19 is tough to beat, built to take the abuse, low geared synchro'd 1st gear...

Yeah thatd definitly be easier i dont know nothin about T19s though. ZF would be good if your lookin for a fifth gear.

The T19 I have has held up to the heavy towing I was doing. They are built pretty stout, and the gears match the diesel rpms pretty well.

Hmm Ill keep that in mind whenever I get me one.

Gents,
GREATLY appreciate the feedback and information. This is great. It's obviouos my diesel experience...or LACK thereof...is showing because I should have thought about the RPM limitations associatewd with a diesel.
I did some checking and I absolutely agree that the T-19 is not only tough enough, but certainly seems to have good diesel engine RPM matching gear ratios. T-19's are plentiful and realtively inexpensive, plus I have a local Tranny guy I've used for years that I trust inherently, so if I get a T-19 that needs to be rebuilt, he's my man. A good tranny guy is like a good dentist..find one you REALLY like and keep 'em !!
Any suggestions on which IDI I should pursue ? 6.9 or 7.3 ? Do you suggest any particular wrecking yard/supplier to buy one from ? Any suggestions on performance upgrades that will provide decent power/torque (i.e. Turbo, injectors, etc.) ?? Thank you !! Doug

7.3 Turbo.. jmho

http://www.thedieselgarage.com/forums/forumdisplay.php?f=23 .. http://www.dieselbombers.com/6-9l-7-3l-bombs-aftermarket/

You can make a 6.9 do most everything the 7.3 can do. The benefit is thicker cylinder walls, the downside is a smidge smaller head bolts. Change to studs and you will be fine. Turbos and free flowing intake/exhaust will really wake these IDI's up.

Very much appreciate the website links from 'Dragogt' and info regarding turbos/intake/exhaust from 'Fellro'. Fellro, saw the mods you made to yours (i.e. 3.25 exhaust, custom intake & electric fuel pump). Thanks agains guys. I'll begin my search and keep you apprised of my struggles, failures and successes. 75hiboy

Sounds liked a plain..