anyone running a 390 in a 76 or earlier f250, could you tell me how far apart the pre drilled holes on your frame are for mounting your towers. I'm asking this becuase im looking to fabricate 390 towers to run a 302 and I'm needing to see if they will bolt up in the most back position on the frame but also line up with the other holes.

 

Why not just get the 302/351/400 towers from a junk yard? Less work and they bolt right into the existing holes, Your frame should have the holes in it already.
Hang on, my truck is an F100 so now I'm not sure what the score is on an F250? Is it 4x4?

Frank

 

I already have 400 towers, but 302/351/400's never existed in 76 trucks so they do not bolt in place, i was just thinking it would be easier to start fabrication with towers that actaully bolt on, instead of having to fabricate some brackets for the towers to bolt on. and yea its 76 highboy

 

FWIW, I had a 460 bolted in a 66 using 76 F-350 Frame stands, brackets & mounts & bolted a 67 289 in a 77 F-100 using 70 F-100 302 OEM Windsor stands/brackets. Any F Series running any FE will have the req'd holes in the right places it's the towers config' that's different in a high boy I believe.

Holes in F-Series engine Cross Members from 65 through 79 are fairly universal. I have never relocated or drilled new holes to swap engines between those years in F-Series chassis. . . .

FBp

 

the 400 towers i have are from a 78 f150 which we notched to fit a 302 in my friends truck, he now has a 390 so i took the notched 400 towers thinking they would bolt up in my truck, only 2 out of the 6 holes line up, further more they do not sit back far enough on the frame for the 302, we had the motor sitting on the towers and it was still a good 2.5inches away from the bell housing. So there must be a difference in frames from mine which is a 76 and his which is a 78. Also would it have anything to do with his being a half ton and my truck a 3/4ton.

 

It's probably the difference in the drive trains that are causing that.

Are the trans X Members sitting in front set of holes or rear set, on the bottom flange of the frame side rail?

They are probably not in the same position on both trucks. The truck with the "gap: is probably in the rear set of holes.

FWIW frames are the same in engine bays from 73-79 in F-100s thru F-350s. In fact,
"from 65 thru' 79 the engine bays are the same", is an accurate statement.


FBp

 

Install the 302 cid to transmission, then install the towers last and mark holes. Then will have to remove engine again, drill marked holes, install fabricated towers.

It will give you a chance to verify if the fabricated tower will work also.

 

yes thats my plan from here, im just going to hang the motor in, bolt it to the bell housing then mark where the towers belong.

 

The 1/2ton and 3/4 ton 4x4 have a different frame. I ran into this also and you must use the 3/4 ton or one ton perches (towers). The 1/2ton had a different frame because they used coil springs on the front instead of leaf-springs like the 3/4 ton and one ton.

 

I thought the frame width was different on the rear, on the 1977.5 and later model F250. I thought the front frame width were the same. I swapped out a 390 on my 1975 F250 Hi boy with a 400 using the 351M engine towers off a 2wd.

 

why would you want to run a 302 anyways? it doesnt have the torque for real work especially in a 3/4 ton, and since it would be overworked anyways lugging around that body and drive trane it probably wont get much better mileage than a 351m/400

 

When time are rough and money is tight, you got ta use what's available to get around.

 

yea I'm just going to run the 302 until i build a big block, i just had it laying around the yard, its bored out with flat tops and an aluminum intake so i don't mind it. and yes the frames are not as wide in the back for 76 and older f250's.