thinking of a diesel swap

[sharkdog]

Just been thinking of swapping a diesel into my 70- f-100(reg cab long bed 2wd) I know a lot of people put Cummings in there trucks but I want to stick to Ford. Power stroke or idi(Harvester) as iv come to find them called seem like the best option but im just wondering what these engines are like in terms of economy/reliability and were any of them all mechanical engines like the first gen Cummings rams? also what auto trans was used with these engines and could I just reuse my stock c6? also what about my rear end? Should I swap it out completely or can I just keep my stock rear end( would I need to change gears?) also what else would I end up needing and what do you think this would cost?

Thanks, Pete(sharkdog)

[Ranchero50]

The 6.9 is pretty heavy for a F100.

I did most of the install on my '71 F250 and there was a lot of work to get it to fit. Raised the cab 1.5", made the mounts and shortened the oil pan. I wasn't a big fan of having the bed raised as it was going to be a firewood truck. The build is in the projects subsection.

I ended up with the F350 flatbed and 1st gen Cummins instead.

[averagef250]

IDI?

My advice would be to keep thinking and spell Cummins without a G.

[Subzero]

The 7.3 would be a lot to put under the hood but from what I've heard it's the best Powerstroke made. I own a 6.0 F250 and my F100 has a 5.9 L. I assume the 360 weights somewhere around 500lbs and the diesel weights around 1000lbs. That's twice the amount of weight up front not including a trans and much more horse power from the diesel. I think the 6.0 is the smallest truck Powerstroke made too. A 6.0 needs maintance done by the book and is very picky about filters and oil. A Cummins 4BT weights near 750lbs and is much smaller dimension wise. It also produces closer to the HP of a 360 V8 and I've heard it is easier on the wallet. I've seen some very odd vehicles with 6.0s in them so anythings possible. You're right it would be a lot better to stick with Ford but it would be considerably more work most likely. I hope this helps some
-Subzero

[ToughOldFord]

Both of the IDIs, 6.9 & 7.3 (pre-powerstroke), are all mechanical and are superb engines, great mileage and dependability and the power is good when in tune. You can't use your transmission, the diesel's use a bell pattern specific to them, but there's a good variety of transmissions you can use, the C6, T19, ZF5, and the fail-prone E4OD.
An IDI would be awesome in a bump!

However, like Jamie pointed out, the IDI would be a heavy monster for an F100, it's 1,200lbs fully dressed.

[bluef250]

Here are data on 4 engines. Your replacement choice may be something else. Engine choice is really related to what you want to do with your truck. Towing or cruising or hauling. At $5 per gallon the 4BT looks really good.

920 lbs 7.3l Powerstroke1999 Ford F-250 Super Duty MPG. I get 18-19 mpg on mine.

360 fe 650 pounds 1969 Ford F-250 gets a combined Avg MPG of 10.00. I got about 15 mpg when first bought mine.

429/460 all iron is 720 lbs with mileage about 9.1 mpg (U.S.)

30-40 mpg. Cummins 4BT engines (750+ lbs) are also easy to maintain, simple in design and can get upwards of 30-40 mpg with performance upgrades.

If you are planning on towing, you should consider updating the brakes to disc's (at least of the front). You should also plan on new front springs.