I have recently purchased a 1965 Ford F-100 Flareside Long bed with the 300 i6 and 3 speed on the column. I have a Caterpillar 3126 diesel with a 10-speed Eaton Fuller FRO-15210B that I would like to swap in. I have a lead on an F350 from the late 80's/early 90's that has a Dana 60 font axle. I'm planning to box the frame and set the '65 cab on top of it. The problem is that I need some information on the differences between the two frames.

Does anyone have the specs of the two frames? (Length Width and Wheelbase) Both are single cab long beds.
Is there a better option besides the 80s/90s F350 frame that would be better suited for the swap?

I have been unable to find the length and width of the 300i6, does anyone have the specs for the 300i6?
As for the Caterpillar, the specs are:
Weight: 1295 Dry with flywheel
Length: 42.5in
Width: 31.4in
Horsepower: 250 (2150rpm)
Torque: 660 (1440rpm)

As for the transfer case i have a Dana 24, is there a shiftier that can be bought aftermarket or will I need to fabricate one?

 

 

The 80+ frames are wider but I don't know the exact amount. There are several threads in the 73-79 dentside forum of swaps of later D60s as they are much cheaper, but the spring mounts don't line up because of this fact. For your swap, the wider frame may be a plus for the engine because the specs you gave make it seem like it will be a TIGHT fit. If it were me, I would look at the engine mounting first and base the choice off that. If you can make the narrower frame work, it would be way easier to mount the body. One other thing to look for is get a frame from a non- highboy F250 (77 1/2- 79) as they are made heavier. The highboys had the heavier frame as well, but were even narrower yet which will probably not fit your engine. With an engine weight of nearly double (and I'm going to bet the tranny has the same issue), you're going to need the extra strength. I saw a post somewhere outlining the differences in the dentside years. I will see if I can find it. For now, here are the specs for your F100.

 

 

 

Found the dentside frame cross section specs in the parts catalog, but they are kind of hard to decipher. I don't have a body builders diagram for a non-highboy F250, but will post the 76 F100/150 4x4 which should have similar dimensions in most cases.

 

 

Copied and pasted from another forum:

300's weigh about 490 pounds.

300 DIMENSIONS (1971 year):
FRT-FACE-OF-BLOCK to REAR-FACE-OF-BLOCK: 725 mm / 28.56"
OAL (FAN-to-CRANK-FLANGE): 931 mm / 36.65"
HEIGHT CL CRANK-to-TOP-OF-BREATHER-CAP: 486 mm / 19.12"
HT OIL-PAN-to-TOP-OF BREATHER-CAP: 690 mm / 27.17"

 

The Cat engine and trans weight what the pickup weights.

 

The 1965 lonbed is on a 129" wheelbase. The 80-90's is 137" I believe. So you will have to address that.

 

I think the wheelbase for the late model is actually 133".

 

Your right, 133" through '97. The Super Duty starting in '99 was 137". Anyway, I would think the newer the chassis the better to handle that engine and they will all require addressing the wheelbase difference.

 

I saw a 3116 (similar dimensions to the 3126) swapped into a '74 F250 4X4. There is not enough room between the frame rails, or between the body and ground to fit it all in without having a butchered hack job, No room for cross members, engine fan, center floorboard, etc.

I am all for unique and making do with what you have, but it won't fit.

 

Well, I guess you're free to build it any way you want, but I personally don't think a 3/4T chassis is up to the task. (think long term, like ten years & 100,000+ miles)
Many will disagree, but would you not be better off starting off with the chassis from a F600/700?? These trucks came with the V636 (aka: 3208), so they are up to the job of holding up the weight of your proposed drivetrain. You can hang whatever diffs you want under it, or if you're in the right place at the right time, you might just stumble across one of four wheel drive versions

 

I think James has a good point. Finding an F600 ish Slick may be a better starting point frame wise.