Hi everyone. So I'm a Ford NEWB. I've always owned Dodge trucks and vans, but decided last year for a change, so I bought an E-150 class-B RV that I have really fallen in love with, and I bought my G/F a 1980 F350 2wd for her Lance 10.9 camper.

I am going to buy her an upgrade (SSHHH!! Its a surprise!) and I'll be inheriting the old F350. Its in beautiful condition in its original two tone paint, less then 100,000 miles and it runs great (400 V8)...

I really want to keep it, and I would also like to do a 4x4 conversion. I understand that 1980 has a "swiss cheese frame" that flexes alot. Would it be a good idea to buy a 1984-ish parts F350 4x4 for its frame, and running gear, or just convert the existing 2wd frame to 4x4 using later axles? Is the 1984-ish frame any better? Or am I going to end up boxing in the frame anyways to get any rigidity? I did a search on the forum but didn't really come up with anything.

I'm really starting to love the Ford trucks and vans.

Thanks in advance.

 

There is nothing wrong with the frame with the holes. If you use the truck for normal everyday duties, normal hauling without overloading it, you will not notice anything different with that frame. They do not flex anymore than the later frames.

If you got t-boned in the side in a accident, you may notice a difference, the one with the holes would probably cave in a little farther. Bridges and trusses have lots of holes in their sides, they are just as strong in the up-and down direction as if they were solid.

Being it's a f350, the 4x4 conversion is not a easy bolt-in like it is for the f100's and f150's. You will need to modify the front of the frame to accept the leaf spring perch mounts and shackles, and you will need to grind the rear leaf spring mounts off your donor truck and drill/mount them to the 2wd truck.

I would get a donor, it would be the best source for parts. I would get one with the transmission you want, that would bolt to the engine. That's a can of worms though, they didn't make the 351m/400 engines for very long before they got rid of them. So you have very few years to get a donor where the trans will bolt up. Your engine has the same pattern as the 460 engine, but there are some differences that need to be addressed, there are some guys on here who know more about that. Your trans choice will be a big deciding factor.

You also need to decide what type of front axle you want. The early f350's came with the dana 50 ttb independent axle. In 1985.5 Ford started putting the dana 60 solid front axle back into the f350 only. So if you want to swap that axle in place, you need to find a 1985.5 and up f350 as a donor. Watch out, everyone wants those axles so they can command a big price sometimes.

What trans does the truck have now? Are you going to use a automatic for the conversion or a manual?

 

First, welcome to FTE!

Second, I agree with Dave - the Swiss-cheese frames are plenty strong enough to do the job. In fact, it isn't the web of a channel or I-beam that goes it the strength. Instead, it is the top and bottom edges, and the web is just there to keep the edges in alignment.

But, if you want to go with 4wd one option would be to find a later F350 as you said and move everything from your truck over. If I remember correctly, the 400 was available through 1983, and many 350's would have come with that engine. However, you can change the perches from your truck to a truck that had a different engine to move the 400 over there. My page on perches explains: Engine Perches - ???Gary's Garagemahal.

As for the transmission, the ZF5 is the way to go for a manual as it has the strength and an overdrive. However, the ZF didn't come behind the 400, and while it will bolt up it won't work without making some changes. Been there, done that, and wrote it up here: ZF5 Behind a 351M or 400 - ???Gary's Garagemahal.

 

The truck is a automatic. I've been eye balling an 1984 4x4 F350 from my local Craigslist that has a 460 (non running)-4SP for parts. As I understand the 400 will bolt in place of the 460 and I can bolt the 4Sp up to it. Correct me if I am wrong here.. please.... The clutch pedal assembly as I understand is just a bolt together kind of conversion. I don't mind the TTB so much as I wont be doing any hard core off roading with it. Its mostly for going camping on BLM land out west with a Lance 9 foot cab over on it where 4x4 may not be a 100% requirement, but will be nice to have in winter.

It sounds to me from your post that it would be a better idea just use a '84 frame and axles rather then modding the original 2wd 1980 frame, install the 400 onto the 4sp, and add the existing 1980 cab and bed... I know that Ill be doing some cutting to the cab floor for the shifter(s)...

Lastly is the frame flex at all dangerous? I can see how much my truck flexes from the rear view mirror as I watch the cab go one way, and the bed/camper go another by sometimes 1 or 2 inches when I go over bumps, or railroad racks.. Kinda looks sketchy to me... My Dodge W350 never flexes quite like that!... but I don't quite know if I should be so worried about it. Our trucks got zero rust so I know that's not a problem here. I just keep thinking about if you bend a fork back and forth enough, it'll break. With that 2500lb Lance cab over thats currently on it, I can't help but think about it..

If the 1984 frame is any better. Ill go for it.

 

I indicated in previous post that I really really want to buy this 1984 F350 with a roasted 460 and a good 4sp to be a parts truck. Are there any real advantaged to boxing in the frame before I plop the 1980 cab and bed onto it? Will boxing in the frame lessen the amount of flex? Or are there disadvantages to boxing in these frames like increased road vibration transmitted to the cab, increased chances of cracking things, or something else that I am missing here due to my lack of experience with these Fords?

Or am I worried for nothing?

 

The 400 will not bolt into the frame where the 460 was. Or, if it does it won't sit at the right height to have the fan clear the shroud and the driveline be at the right angle. And it will probably be in the wrong position front/rear. Go read my page on perches - link in my previous post.

And, while the 460's transmission will bolt up to the 400 it won't work. Again, read my page on a 460's ZF5 behind a 400 as most of it applies. Link in my previous post.

As for the clutch pedal assembly, it will bolt into your earlier truck. However, you'll quickly discover that the '84 has a hydraulic clutch linkage and yours isn't set up for that. You can drill the holes in the firewall to accept the clutch master cylinder, so that's not a big issue. On the other hand, Ford had some problems with the firewall cracking on the early hydro clutches, and I wouldn't convert to hydro w/o installing one of the firewall braces to ensure that doesn't happen. Terrapin has a brace for that.

 

I think you are worried about nothing. I've not heard of frame problems with these trucks, and there's been frame flex on Fords for quite some time. I remember my 1972 F250 would let the cab go one way and the 9 1/2' self-contained camper go the other, but there was never any problem and we drove it many thousands of miles.

 

Thank you. This is great info as I educate myself on Ford trucks. Couldn't I just use the 400 perches (I read your links...) that are original to the 2wd frame? Or is the X-member so different that I can't so I'll have to do fab work?

I also want to use the 1984's original 4SP transmission with the 400 V8... If I don't like it, I'll go 5-sp. I'm guessing that the items highlighted in the ZF5 link are the same for the earlier 4Sp's in relation to adapters...

Thanks again. Sorry that I am such a Ford NEWB. Ive been googling and researching as much as I can....

 

Yes, you can use the perches from the 2wd frame. I thought you were missing that step and didn't want you to overlook it. And the 4wd's crossmember should work fine.

On the tranny, the biggest issue is the placement of the flywheel. So, you will need to get an adapter from Tim Meyer, which is made to my specifications as I seem to have been the one to figure out the clean way to make the swap.

I think the 4-speed's input shaft is smaller than that of the ZF5's so you should be able to use the clutch plate from the 460. And, you will need to find a flywheel for a 400 and use a pressure plate for a 400, as the 460's pressure plate won't bolt to the stock 400 flywheel. However, I have it on good authority that Tim has a 400 flywheel that's been drilled and tapped to accept a 460's pressure plate. It is mine, and I've changed my mind about installing the ZF5 behind the new 400, which Tim also has. Instead, I want to put the ZF in Big Blue and go with an E4OD in Dad's truck. So, my flywheel is available and it has already had Tim's work done.

As for being a Ford newbie, I was as well several years ago. I grew up with Chevys, and swapped transmissions between lots of engines w/o problem. So, I was blown away with Ford's "better idea" to have a different bell housing bolt pattern for each engine series.