frame measurements, please

[havi]

Anyone got measurements for the frame on a 4x4 F150? Here's what I have at the engine mounting area:

1: outer frame rails across at 34"
2: inner frame rails across at 28.5" (behind engine perches and reinforced area)
3: inner vertical area between perches at 26.5"
4: perch bolt holes centers across at 30.75"

Just want to verify these, since I'm trying to do them with the engine still in.

 

[DNFXDLI]

Measurements I took from the bare frame:

Outer 33-1/2''
Inner (behind reinforcement) 28-1/4''
Inner vertical 26-1/8''
Perch centers 30-1/2''

 

[havi]

Thanks. It seems with the abuse these frame have been under over the last umpteen years or more, they don't really measure up exactly do they? Or were the factory tolerances that soft? Either way, your numbers are close enough to mine that with the oval shaped holes in the perches for the motor mount bolt, I think I'll be ok. (maybe with the engine still in it pushes the frame around)

So on to the next question, here's a pic I made real quick to get a visual of what I'm looking for now.... the distance to the center on both an FE and 351/400, and ultimately how much offset to the passenger side the engines are. Are they same between the engine families? Or are the FE's offset more than the 302, or 351M, etc...?

 

[DNFXDLI]

No idea on that...I can measure the offset on mine though if you want.

 

[m78]

I'd be willing to bet the factory tolerances are were laps.

So what measurement do you need ? The O/S frame trail to center of engine mount ?

 

[havi]

Center of bolt hole where the motor mount bolt goes through to the outer edge of the perch on top of the frame rail. That way I can figure out the total offset. Then reverse the numbers to design my own perches for the Fairlane.

 

[havi]

Got the 351M/400 perch measurements added.

Passenger side:
I measure 4.25" between the top frame holes, 5.5" from the rear top hole to the mount hole center, and 6.5" from the front top hole to the mount center. I think the mount hole is 1" offset towards the front from the rear top hole. This gives me 12" from the bell surface to the mount hole on a 351M/400.

I have an FE, but no motor mount to put on to get an accurate measurement. So I have 14" to the forward block mount holes from the bell surface, and 12" from the rearward block holes. Having a motor mount would make life much easier. The FE uses the 300 perches. I have a 300 in my '79 Bronco, and the top perch holes measure 3.38" and because the engine is in, I can't measure to the mount hole from the top frame holes, but they look pretty even between the two.... so guessing the mount hole is half of 3.38", or 1.69". The bell surface to mount hole is about 17" and naturally the perches are in the forward holes of the frame. There's no way the FE can go into the same holes and make 12-14". So the 300 perches have to mount in the rearward frame holes, but the spacing is 3.38", so a new hole would have to be drilled in the '77.5-79 frame. Doing this, puts the mount hole back farther, but I don't know where exactly. That is what I am trying to figure out.

So if anyone has a '73-77.5 F150 4x4 frame, I would like to know the distances between centers on the top bolt holes, already knowing the forward holes should be 3.38". I would guess the rearward holes are 3.38" as well, and so these frames are drilled differently than the later 70's frames. I would like to confirm this.

Secondly, If anyone has an FE with a 4x4 motor mount on it, I'd like to get the 'bell to center of motor mount bolt' measurement. Thanks.