Previous owner swapped a ‘69 391FT into the ‘82 F800 5+2 I bought a few years back. Looks like this motor is shot and am waiting on a tech friend to confirm. I’d like to start hunting a replacement, drop in engine and just don’t have enough knowledge. Any recommendations on a modern day 391ft equivalent I should look for that would not take to much modification to install? I don’t have a lot of money in this truck and can’t afford much. It’s just a farm truck with plans for minimal, light use.
Myself would first look in to rebuilding the 391 . http://www.northernautoparts.com/part/ek-ek0556
Thanks for the link; that option will be on table as well. I was under the impressions rebuild parts are getting harder to find for this motor. The old timers at NAPA were about the only people that could help me when just trying to get an oil pan gaskets. The other auto stores can't do anything without a make and model!
Our local NAPA store is pretty sharp as well on parts . If the computer don't show it they reach under the counter and pull the ancient text book out to look up the part number . What's going down with the 391 ? Oil use , blow by , engine miss ? Those are pretty good engines . Have a 361 in a F- 600 digger derrick truck . Rebuilt my buddy's 361 in his cabover Ford dump truck . Had to bore 1 hole out due to wrist pin damage . HeavyEquipmentForums
Hopefully the crank in that 391 is good or can be undersized, steel 391 truck crankshafts are hard to find that are any good. The biggest expense in most cases are the cylinder heads. Those early years could or could not have sodium exhaust valves and the valve seats need to be changed to hardened seats plus FE block Ford engines are hard on valve guides. Plus it's wise to plan on surface grinding the cylinder head deck and exhaust manifold surfaces. If the heads need major deck surfacing it's wise to have them deck the intake manifold also. Other wise intake vacuum leaks are very possible. Plus valve stem heights need to be on the money. When assembling the upper end of a FE block after cylinder heads have been surface ground it is a must to check that you have the proper length push rods installed so the self adjusting lifters operate properly. The use of two adjustable push rods is necessary to get that right. It's critical to get that right to achieve good vacuum. FE block Fords have gotten expensive to rebuild, just finding good core heads to rebuild is tough. Also the rockers and rocker shafts will need to be disassembled and inspected, those parts had a real tendency to wear out and often over looked or even cleaned on a rebuild. Truck Shop
Too far away, but look around something will surface. https://kpr.craigslist.org/hvo/d/1978-ford-f750-truck-with/6726253167.html Truck Shop
The 391 FT engines are easy to find here and i have never had a problem finding parts.If you was closer i know were there is a rebuilt one. I have a truck with a 330FT i use all most dayly that being said i dont think they are a great engine but it will bolt up in your truck. My truck is older it came out with a 292 i am not the bigest ford lover but the 292 is one of the best engines that i have ever owned it was worn out but it would run circles around the 330 that i got cheap with low miles on a rebuild.
If it is just for light use it should not really matter if it is a fancy steel crank FT engine, right? You could just look around at junk yards for a 352, 360, 390 pickup truck engine I should think.
Fact is the FE block car or truck engine has not been produced since 1977, the last ones rolled off the line 41 years ago. There might be some laying around but there's a reason there laying around. Most blocks are all ready punched at least .040 and those rebuilds were done in the 80's and worn out. The realistic side is most of what's out there is shot and needing a major. And to know what your really buying a person better remove a head and measure bore and stroke. 390=4.50 bore 4.00 stroke 360=a 390 block with 352 crank and rods. Truck Shop
The motor is locked at the moment, apparently from water getting in it. We move the truck 6-8 months ago and it was running ok. Apparently where we moved the truck to didn’t have the protection from the elements it previously did. (Less trees) With the above normal rain fall and two hurricanes, it appears to have got a good soaking. We are going to dump all the fluids, and try soaking it to free up and go from there.
My original questions still stands though. As old as the engine is; If I was to have it rebuilt, since I would have to hire it out, rebuilt parts and labor are not going to be cheap. Plus I’d have to find some one that actually knew the motor so it is done correctly. Would that cost be better spent to a newer, parts friendly motor. As Birken alluded to; is there a alternative truck motor out recently that with minor modifications in a junkyard I could keep my eyes out for, that would be better in the long run. I know of several diesel engines options that could be go in, but would be probally be cost prohibitive, vs Ford xxx motor found in pick up truck x that could potentiall drop in with minor mods. This is good feedback. I appreciate it.
I am 90% sure the only engine that shares the bell housing pattern is another FT or FE engine. As stated they have not been used since the late 70s but as near as I can tell they were the pickup and medium truck engine through the late 70s and continued as medium truck FT engines until the early 1980s.
Drop in a 460 and tranny?
Had not thought about the bellhousing. Since this is an ‘82 and pretty sure the original motor was the diesel version. (I’ll see if I can find a VIN decoder) I assumed the previous owner just swapped in the 391. I guess I need to confirm what transmissions it is.
I kind of wonder also if the 391 FT flywheel would be guaranteed to bolt onto a regular pickup FE crankshaft. A 460 would be nice but if it is just for putzing around the yard, I would pick the cheapest engine that would make it go again.
aside from the obvious; I had a 429 engine show up in FAcebook marketplace that a mechanic is selling. Even if it could work in my truck, I can’t afford it as he wants $2500; but the ad said it was built for a heavy duty dump truck (and customer didn’t picked up!) or a 370 upgrade. That started me wondering about replacement options.
If you go the used route make sure and tell them you want to see it run and what the oil psi is hot at idle. 25 lbs minimum hot. Truck Shop
If it was a diesel, likely it was a 3208 Cat or a 8.2L Detroit V8. Good possibility that 391 has an adapter flywheel housing to mate to an SAE #3 transmission bellhousing. That will increase your chances of putting in anything you like.
There is notheing that will bolt in easyly put another FT. I have fixed up alot of junk in my time because i am cheap is your truck realy worth fixing? If it has sat very long it will always cost 4 times more than you think it will to make it usable.
Do you mean there would be something wrong with an FE or would that fit also?
A FE or Ford Edsal may work but i dont know about the flywheel and if he has airbrakes the FT or Ford truck has a longer front crank shaft snout to drive the belt driven compresser. I had a buddy almost beg me to remove a f750 from his farm that had a good one that he had rebuilt but here old gas hyd brake trucks are just scrap iron.
you could check out an old 360 from a mid 70's F250. the crank snout may be the same, just a 2 groove pulley instead of a 4. when I worked at a ford dealership we changed a lot of the FE engines, light duty and heavy duty. quite often the wrist pin moved over(circlip came out or broke) and gouged a groove in the cylinder. the heavy duty engines had a different cam and sodium-cooled exhaust valves, different intake(4 bbl) and distributor(different advance and governor provision) and sometimes different water pump also oil pan. all that stuff is easy to change if the basic engine will work
That's exactly what happened on my buddy's 361 . Pin boss on the piston broke away and snap ring came out . Got most of the wrist pin gouge out at .030 over bore . She's good for another 10 years . LOL !
What was the symptom when this happened? How long did it run before teardown? Drive or tow back to the shop?
It was using oil & fouling out spark plugs . No idea how many miles / hours it had on it . Other than the oil use engine ran fine , no funny noises or knocks . Customer just drove it over & left it with us . I was surprised to see multiple busted piston skirts and the one with the loose wrist pin . It was in a 1967 Ford C 700 cabover . " In framed " it with new pistons and rod & main bearings . Looked like this truck .
Of all the old school trucks, I really liked those cabs. For an oldie, they were comfortable and quiet and the windshield was enormous and wrapped all around. A little hard to climb in and out.
From what i remember it would knock then very shortly time the engine would be a total junk. I cant remember one that could be fixed. They started puting floating pins in SB chevys to race i thought thats not smart and they had problems with the keepers. At high RPMs they were junk fast. The also made bumpers to go in the pin ends so if something happen the bumper just rubbed the walls.Buy the time i started rebuilding engines i had saw alot of wrist pin keepers problems i was afraid of them.
I had one of those old Fords as an equipment fueler, had an 1160 Cat and a 1500 gallon tank. The shift linkage and 5 speed trans was so worn out, I replaced the trans with an Allison 643. Made a great truck, but took a bunch of work to convert.
we had an old (1965) C700 on the farm. hated that shift to reverse, 2nd or 4th gear. had to use your palm to push the stick forward otherwise you would jam your knuckles against the dash
The shifter was mounted to the cab it wasnt a real good deal all so they didnt cool well becace or several things. I think the cab was made by bud for Mack they didnt like it but ford did.I have saw some realy difrent deals made from the c Fords . I saw a c800 single axle tractor with a 300 6 in it i think it was a spoter for sale low miles like new,the other day at the junk yard there was a c750 with a very big utility bed that had a crane on it that looked like it should be on a crane not on the back corner of a truck it had every thing and a 60.000 pound winch mounted under the bed. If i was rich i would have bought it and restored it there also was a c600 with a very nice equipment bed or early roll back at the junk yard.
I remember reading that Ford used that cab from 1959 'til 1986... One of the longest lived cabs ever. I think Ford was using it before Mack tried it out. Then Mack went to the MB series cab that was built by Evans, the same company that built the cabs for the White Compact series. Hot in summer, cold in winter. Leaky steel box without much for creature comforts.
Agree fellers ! The shift linkage on the C models takes a little getting used to .
Those Glasspacks sound good, doubt they would last long on a working truck.
We had one that was a 1989 model, and I think they were made a little after that. Story I heard was that at the factory they had big rubber mallets to make the bolts line up, the stamping tools were so worn out. The ones I used, the heater was a big old box on the right side that stuck out into the passenger legroom a little bit, and it would roast you like a turkey. No AC of course but nothing had AC back in those days. They did have a wind wing and another knob you pulled so air came straight up the front and center, you could see right out onto the road when you opened that one.
Actually, I think you are right, 1989 may have been the last of that series.
I have a 1990 C8000 with AC
First year for the Ford Nalley's potato chip truck {C model} was 1957, in 58-59 & 60 those had quad headlights. Mack also used that cab from 58 to 62 IIRC and the early Macks had quad headlights also. IMO Those trucks were piles, we had one on the farm---turd. Funny story about a C model-The boss towed it in and the guy was moving from Alaska to Illinois. That wonderful 391 grenaded, shot the fan off the end of the crank and bent the nose of the crank and #1 main cap plus the fan tried to come inside the cab by the drivers feet. Chopped all kinds of holes in that cab. He bought a used engine and radiator that we installed. Got it running and took it for a test drive wouldn't up-shift. The governor had exploded in that wonderful Allison which in turn dropped from 4th to 1st at about 45 mph and the rpm took care of the rest. left one hell of a compression scratch on I-90 Ryegrass summit. Truck Shop