Bad Swap

plumbobaloo · #1 (**permalink**) 02-03-2008, 01:46 PM

I Have A 76 F250 That Came With A 390 And A C6 Tranny. Moters Toast , Gunna Rebuild Soon. In The Mean Time I Got A 351m Free And A C6 That Will Bolt Up To It.other Than A Headache That I Know Im Gunna Get What Will I Need To Complete This Loonytoons Swap Any Advise Will Help. Oh And The Guy That Gave Me The Moter Said It Came Out Of A 84 Bronco ? If That Helps Any.

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Matts72 · #2 (**permalink**) 02-04-2008, 01:03 AM

How complete is the engine, because nothing from the 390 will fit on the 351M, except the power steering and alternator. You will need 351M/400 motor mounts and towers from a 77-79 and you will probably have to modify your current exhaust or build a new one.

I would personally just get working on the 390 ASAP and you will be done with it in a few weeks if things go pretty smoothly. I would think that most machine shops could have a 1 week turnaround on block work assuming you got all the parts together ASAP.

Good Luck and welcome to FTE!

plumbobaloo · #3 (**permalink**) 02-04-2008, 09:15 AM

thankyou for the welcome and for the info. the moter is complete exept for the starter and dist , but a friend has a dist i can throw at it. but yep my line of thinkin is about the same as yours on getin the 390 done. love the fe had one in a 67 fairlane, best moter i ever had, about the best car for that matter. wish i still had that one sold it for $200 back in 82, ouch oh well .done dumber, but not much. anyway think ill just redo the fe, with a few mods of course, and put the 351m back in a corner somewhere or maybe, stick it on that old go cart frame out back...... hmm. thanks again.

havi · #4 (**permalink**) 02-04-2008, 08:42 PM

by the time you get the 351M into the 76 F250, you'll have swapped in everything from the radiator to the driveshaft. Just get the 390 done and back in, and save yer self the headache. In the meantime browse the ads for another '67 fairlane.

gradrgy · #5 (**permalink**) 02-19-2008, 07:46 PM

I don't know what the problem is. I installed a 351M in my 68 F100 several years ago. All I had to do was change out the clutch housing and fabricate a bracket for the clutch linkage nylon "ball", because the housing I used was set up a little different than the original. It was pretty simple to make it work.
I used the original transmission and drive line. Didn't have to change anything. The original radiator worked fine.

havi · #6 (**permalink**) 02-19-2008, 08:59 PM

FE frame perches set the engine 1" off from the 302/351W/351C/351M/400 perches in a '76 F250.

Matts72 · #7 (**permalink**) 02-20-2008, 12:03 AM

gradrgy-

Its not a lot of work to do it, but its a complete waste to do all that modification to only switch it back in a few weeks or months. There isn't anything wrong with the 351M.

redvalley · #8 (**permalink**) 03-05-2008, 09:50 AM

Quote:

Originally Posted by havi

FE frame perches set the engine 1" off from the 302/351W/351C/351M/400 perches in a '76 F250.

FWIW a 351w droped right into the frame perches on my 76 f100 w/ 360 fe. I wouldn't think the mounts would be that different from a f100 to an f250 (same motor/same year). Any way I agree with the other guys fix the 390 or sell the 351m and get another fe motor to put in there while you take your time working the 390 over.

havi · #9 (**permalink**) 03-05-2008, 06:13 PM

I've heard both stories several times on the FE to others. My experiences only stem from 4x4's. In the 4x4's looking at the perches between the two, you can see a difference. Where the transfer case bolts to the driver side frame, it has to be pretty much spot on. Where the trans. bolts to the crossmember, there's enough "oval" to take up some of the difference. I've noticed, also, that there's 2 different crossmembers too, between the 4x4's. Perhaps one for auto, one for manual. Between F150's and F250's the differences are really only in the suspension, for the most part. It's been a month, I wonder what happened?

I don't know if this makes a difference or not, But most everything I was talking about was 77-79, maybe the 76 and earlier frames had different mounting points.....probably subtle if any?

redvalley · #10 (**permalink**) 03-05-2008, 11:19 PM

I did have to make a new cross member to clear the front driveline (did a complete drivetraine swap from an 88 f250). The location of the crossmember was perfect though, I even used the stock member (slightly worked over) for a little while. I also switched from manual to auto in the swap. Could have just been a fluke though. Sure hope he didn't put that 351m in there though.