The Diesel Garage banner

1 - 18 of 18 Posts

·
Junior Member
Joined
·
12 Posts
Discussion Starter #1
Hi, Ive got a 78' F250, auto trans, 4x4, with a 460 gas hog that won't pass smog. Rather than putting a valve job in it and still getting 5 mpg, I thought why not convert to diesel. So I'm looking for an 87-93 International 7.3 liter IDI engine. A complete vehicle would be ok if the price is right and location is Northern California. Can anyone help? Thanks, much appreciated.
 

·
Senior Member
Joined
·
2,063 Posts
I wish you good luck, but trying to find a 35 year old engine that is in good shape may pose a problem.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #3
I was afraid of that. I was thinking a complete vehicle, so I'll have things like the fuel tank, etc. included. It needs to mount to my stock automatic trans and motor mounts. An 87-93 F250 with a 7.3 liter IDI engine is what I need, I think. Could some one please advise me if I'm barking up the right tree?

I know what you're thinking, just get a different truck. But this is the company truck that has been with the business since 1978 and it's outlasted everyone including the owner. It's got the company name on it and is recognized all over town as a icon. The truck represents a business that just won't quit, is reliable and you get the idea.
 

·
Senior Member
Joined
·
2,063 Posts
I have a 94 dodge with a 5.9 and 5 speed. Drop me a PM if you are interested.

In my opinion the easiest way and least expensive would be to find a drivable truck and part out what you have. But we tend to become attached for different reasons to things, and just don't want to part with them. Example I have a 1965 riding lawn mower, I bought it new and while my 2010 Cub does a much better job I still keep the old thing (just to have around).

If you just want to keep the old girl around you can look at some of the conversions listed here. They are a lot of work, if you want to do it right.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #6
I could rebuild it but it gets horrible fuel mileage, and it must pass a smog check every 2 years. I could spend nearly as much to rebuild it as it would be to put a diesel motor in it. In California the seller is responsible for passing smog, so I could give it away which I don't want to do. I could scrap a good truck which I don't want to do. It is becoming a collectible model. I get a few comments on it once in awhile. Nothing like my old Chevy's though. I think making it a diesel would only increase the value, barely, to what I'll have in it. But there comes a point where collectible vehicles no longer go down in value. I'm close to that in my eyes.
 

·
Senior Member
Joined
·
2,063 Posts
A real collector is looking for a vehicle just the way it rolled of the assembly line. And preferably with most options available.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #9
I'm finding a few leads out there, mileage ranging from 150k to 300k
My thoughts are if the modifications done make an improvement in the functionality, a collector won't mind so much. Not too many collectors scoopin up vehicles that get 5mpg.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #10
The more I learn about my original 6.6 400 cid small block, the more I'm considering a valve job (new Edelbrock heads). There are limited aftermarket performance parts available for this motor (mostly stuff that interchanges with the 351 motor). The deciding factor would be, can it still pass smog and can I improve fuel economy? Otherwise going diesel would be a good alternative with a complete donor vehicle. At the very least I'll save the original motor and build it later. Any suggestions?
 

·
Senior Member
Joined
·
2,063 Posts
Buying a engine and a adaptor plate for the transmission is only the start, all the small brackets and little things take time to make. And the issue of smog testing is another issue.

I had a 78 f250 with a 460 and a automatic geared 3.73 back in 78 it made 9-11 mpg with a SA250 Lincoln welder and torch and tools. You may find a good overhaul will help your mileage. Second thought is to add propane fuel system, on a old truck like that you would loose a little bit in mileage (about 10 percent) and loose a little power (there again about 10 percent) but where I live I am buying propane for 1.85 a galion. Also you will need to check state a local laws but here in Texas 96 and before are exempt from air emission If they are on CNG/Propane. Newer vehicles must have a EPA approved system.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #12
Just keeping the old girl on the road is important to me, so I think an overhaul would be the best, but I would like to change the intake manifold to use a 4bb and other modifications that improve performance while still passing smog.
 

·
Senior Member
Joined
·
2,063 Posts
It may be a CA. thing but all the 460's I have seen in pickups were 4br. Ford did have a bad habit of installing something other than what it should be. I had a 1973 f150 with a towing package that was suppose to be a 390, I bought the truck new, after I sold it the man who purchased it overhauled it and it turned out to be a 410 or 406 I don't recall exactly. I don't know were thing got changed up but I did not do it.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #14
I mistakenly called it a 460. It's a 6.6 400 with a c-6 trans . You make a good point, I bought it from the original owner, the sales person told him it was a big block and that's what info I got from him.
 

·
Aimless Wanderer
Joined
·
929 Posts
I mistakenly called it a 460. It's a 6.6 400 with a c-6 trans . You make a good point, I bought it from the original owner, the sales person told him it was a big block and that's what info I got from him.
That 400(M) engine you have is not a bad engine if left alone. They were a bit weak in the lower end but usually delivered pretty good economy for their day. I'd install a different carburetor than the original Ford two barrel as they were never very good even when new. I think they called them a variable venturi style. I rebuilt several but they were always presenting problems.

If you go with a valve job, open up the valve pockets and ports a bit. That was a "smog" engine no doubt but could be made to run well with a bit of work. Head, and a little intake port work, coupled with a nice Holley, or Carter 4bbl would really wake them up. Don't push them real hard as the crankshafts were weak after the 1973 model year, (automobiles) which could be different in the truck line.

If you do rebuild the engine, have it balanced. They will run unbelievable smooth if done right. I had a couple of Torino's, and a Ranchero with 400(M) engines and never had any trouble out of the ordinary with any of them.
 

·
Junior Member
Joined
·
12 Posts
Discussion Starter #17
It's the largest cubic inch small block Ford made at the time. It has a taller deck giving it a longer stroke and the heads are set farther apart giving it the appearance of a big block. Also the casting at the back of the block is the same as a big block allowing use of big block transmissions. It's like a 351C on steroids
except the steroids were a placebo. Thanks to emissions regulations it lacked hp and got bad fuel mileage. There are some who say it can be built into a good hp engine, solid too. I have yet to hear of anyone doing that and still passing smog in Ca. Well anyone with a 78' like mine that is still required to pass a smog check every two years. Anyone got any suggestions?
 

·
03 f350 xl 7.3 2wd x-tend
Joined
·
119 Posts
I'm not sure if its still true, but a few years back when I was looking into putting a 4BT in a CJ-7 I had, I called the referee and he told me if it didn't come in that model vehicle in that year than you have to go newer, if going to a different motor it had to be newer than the vehicle and out of something in the same weight class. Like a half ton motor in a half ton truck, couldn't put a 5 ton truck motor in a 1/2ton truck. So before you buy anything double check with CARB's smog department.
 
1 - 18 of 18 Posts
Top