I'm planning on swaping an older 12 vavle cummis and drivetrain into a 77-79 F-250 or 350 and was wondering if anyone had any helpful advice before I start.Thanks

 

Manual or auto tranny? early Gen 1 or 94-97 gen 2 12 valve. The earlier rotary motors are shorter length wise by 3/4 of an inch they use a shorter fan hub. Also the Gen 1 motors slightly simplier since thier intake system is smaller than the later 3" intake and turbo setup on the gen 2's. The dodge uses a hydrolic clutch assembly. The NV 4500HD is an excellent tranny though it will require an adapter sleeve, an aluminium adapter and a dodge NP205 input main shaft to marry up to a gear drive 205 t-case from a ford. Email me if you want to get into detail i will do my best or if you are looking to have it done i can recommend a MT based out fit that does them, they were instrumental in the development of my Freak Dorf.

Dusty


Why Buy new when you can build and tailor it cheaper?
F-350 4x4 ext cab Short Bed Green Monster, it is now Sporting a 300HP 715lb/ft Dyno rated 5.9L 12v Cummins diesel w/ NV4500 5spd and custom NP205 ford T-case w/ rear spicer 1410 yoke, Converted to Sterling 10.5 gears w/3.73 gears using the 41 spline pinion and 1410 U-Joints, Power-Lok equipt Dana 60 front, 33's on 16x8" Outlaw II's. (Used to have)205000 miles, Mass air 460 w/ performance heads and a E40d to 5spd conversion and Doug Thorleys. Old EFI 460 @10 MPG to the 12 V @ 23.2 MPG @ 75 MPH and loving it.
My other toy is a '69 CJ-5 354 Hemi 4 spd 4.88's 32x12.50 MThompsons w/ power-lok 44 rear.

 

What is you opinion on a Cummins vs. a powerstroke conversion into my 78 F-250?

 

Forget about trying to swap a PSD into your 70s truck as the PSD has a thicker wiring harness hanging off of it than all the wires combined in your old 79. The only other diesel to swap into your truck would be a 7.3 IHC the same engine used in the early Fords. The Cummins is a good engine but is kinda of a Dog with no go fast goodies so plan on putting some money into performance mods.

Good Luck

 

What are you going to use the truck for, I like the cummins for long continuous operation, @ a consitant 20mpg and better and the ability to smoke the tires if i desired while pulling my gooseneck i am happy. plus it only cost $275 to get 330 HP 750 ft/lb flywheel torque out of it and it now rearwheel dynos @ 298.3 HP and 714.6 ft/lb, I also added the larger exaust turbo housing for $100 to drop exaust temps 175 degrees. there are a wide variety of performance parts for both. I think that the assertion that the cummins is a dog is without foundation. A big part of it is gearing a PSD as a V-8 loves to rev and the I-6 was never designed to do such, this makes the PSD a more uiniversal fit. At the same time what do parts for each engine cost, rebuilds etc? how long are you going to keep it and what do you expect out of it.

It is one of the most widely used engines from skidders, to class A motor homes, freightliners and boats.

Kenworth is right stay away from the wiring involved with the PSD it would really be a headache plus your firewall would require remodeling since the PSD down pipe would require more room behind the engine.


My old 95 PSD cost me a fortune in injectors a little over 100K miles, i think the final bill was upwards of $2700 including the replacing of the cam position sensor which failed. a set of cummins 12 Valve injectors cost $369 from cummins northwest and $60 labor/ 1 hr to install and are mechanical. So you need to run the numbers and consider all variables a 7.3 IDI would be an interesting choice but that also has its ups and downs it would definately benefit from a turbo and a screwdriver to the pump's timing. Another thing to consider an I-6 12 valve uses an inline high pressure pump which has twice and three times the life span of a Rotary pump (used on earlier cummins and also on V-8 IDI diesels) Also when you do this keep in mind tire size, gear ratio and RPM performance range. My cummins comes online from idle but hits hard from 1500-2200 and all the way to 2400 then it dies, my PSD was a little sluggish in the lower RPMs but really showed promise in my driving RPMs from about 1800 or 2000-3200 and never died off really but it also had 4.10's which worked well. the cummins works better with the 3.73's and 3.54's and 33" tires. Lower RPMs

Good Luck
Dusty

Why Buy new when you can build and tailor it cheaper?
F-350 4x4 ext cab Short Bed Green Monster, it is now Sporting a 300HP 715lb/ft Dyno rated 5.9L 12v Cummins diesel w/ NV4500 5spd and custom NP205 ford T-case w/ rear spicer 1410 yoke, Converted to Sterling 10.5 gears w/3.73 gears using the 41 spline pinion and 1410 U-Joints, Power-Lok equipt Dana 60 front, 33's on 16x8" Outlaw II's. (Used to have)205000 miles, Mass air 460 w/ performance heads and a E40d to 5spd conversion and Doug Thorleys. Old EFI 460 @10 MPG to the 12 V @ 23.2 MPG @ 75 MPH and loving it.
My other toy is a '69 CJ-5 354 Hemi 4 spd 4.88's 32x12.50 MThompsons w/ power-lok 44 rear.
https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=4039&.jpg
https://www.ford-trucks.com/user_gallery/displaythumbnail.php?&photoid=474&.jpg

 

Is that Cummins motor thats in your truck out of a Dodge or is it a standard Cummins engine usually Dodge has the one long tappet cover where as yours has the individual covers. It must be a b*tch to get the rear tappet cover off being that close to the firewall. Diesel swaps are good if you got money but if your on a budget forget it I was going to swap a diesel into my 88 F-Superduty but for the amount of work involved I could buy a diesel 450 cheaper.

 

It is a Mopus motor, the long tapet cover for the 12 valve motors are removible and i wasted no time discarding it. LOL the rear cover is easy to get off once the one in front of it is removed, you are right though it is all tight in there.

Cost is a matter of preperation and shopping, i sold my 460 parts and cut the conversion price tag by 2/3 most the time i wouldnt have been that lucky a complete motor tranny and t-0case can be bought for 3000 with 179000 mile on them to 4500 with 70000 miles, it is best to find a ford or dodge that has been wrecked buy it at an insurance auction for 4-6K then sell what parts you can on ebay and cut the cost. either way it is alot of work and you still have a truck that has x# of miles on it in body stress and frame fatigure including axles and springs.


Why Buy new when you can build and tailor it cheaper?
F-350 4x4 ext cab Short Bed Green Monster, it is now Sporting a 300HP 715lb/ft Dyno rated 5.9L 12v Cummins diesel w/ NV4500 5spd and custom NP205 ford T-case w/ rear spicer 1410 yoke, Converted to Sterling 10.5 gears w/3.73 gears using the 41 spline pinion and 1410 U-Joints, Power-Lok equipt Dana 60 front, 33's on 16x8" Outlaw II's. (Used to have)205000 miles, Mass air 460 w/ performance heads and a E40d to 5spd conversion and Doug Thorleys. Old EFI 460 @10 MPG to the 12 V @ 23.2 MPG @ 75 MPH and loving it.
My other toy is a '69 CJ-5 354 Hemi 4 spd 4.88's 32x12.50 MThompsons w/ power-lok 44 rear.