79 460 flywheel swap
 

78 f250 4x4 single cab np435 tranny.
I did the swap on a my truck from a 400m to a 460.
But I am not satisfied with the setup of the tranny to engine.
I used a flywheel from an 82 460 since they are both externally balanced, I used a 400m clutch from the same year and a throw out bearing
The pilot bearing is from an 82 as well. I had to place a 3/8 spacer between the block and the bellhousing.
I wanted to know a few things.
1. what stops the bellhousing from meeting the block without the spacers? Is it the input shaft hitting the crankshaft or is it the input shaft hitting the pilot bushing?
2. Are the L and L flywheel machined thinner to fit in the bellhousing?
3. Will a slightly misaligned clutch pad cause the engine to vibrate? Cause the flywheel should not be the problem since the 82 460 is the same as an 79 460.
Thanks for the help

L & L Products has the kit to swap from 400 or 351M to 429/460 using your 351M/400 bell housing. It will give you proper back spacing. Takes the headaches out of swapping.
http://www.landlproducts.com/list.as...cID=7&scID=130

Another person did this swap but used the flywheel from a 390 on an older 460.

Which year 460 did you use ?

Also it's 400.. not 400M

it is 351M ...400

Actually, in posts like https://www.ford-trucks.com/forums/6...0+flywheel+460
, the 390 flywheel in question was used on '79 and newer 460, which were external balance. '78 and earlier were internal. You might contact L&L for more info on this swap.
Let me know if you like your engine swap, and if it was worth it, pros/cons of each.

Isn't the 390 also internally balanced?

That is correct, that is why thats the flywheel you need for the 78 and older motors.

The reason for the spacer is so the clutch will not hit the belhousing. To confirm this, you can put some plumbers putty on the edge of the clutch, bolt it up, see how much clearnace you ahve. I did this along with the input shaft to see where everything goes. I used a flywheel from a 360 3 on the tree, did not have any issues aside from needing special flywheel bolts that had low profile heads on them. The springs on the clutch disc hit the head of the bolts... I used a Centerforce Dual Friction clutch and throwout bearing. The clutch "pad" I assume you mean disc will self center on your input shaft. If something is out of whack, it can possibly vibrate the transmission to death. THe important thing to check is the trueness of the belhousing in relation to the centerline of the crank. There are instructions on how to check this, with the proper tools. You'd need to have everything apart to check it however....

on mine,the bearing retainer,which is where the throwout bearing rides,was hard up against the clutch hub,preventing it from backing off the flywheel.I ended up taking about a 1/2" off the end of it and it seems OK now

It took me a minute to figure out what you said, but you are saying that the sleave that the input shaft is covered by, and what the throwout bearing rides on was too long, you took 1/2 inch off of it, and its ok? I recall when I did my swap that there was not much room for the throwout bearing to back up off of the clutch fingers, but there was just enough room to get the job done.

yes,lucky for me,the spinning clutch wore off about 3/8'' of it.part is aluminum,some are steel.Couldnt get my clutch to work,so I took it all apart,found this to be the problem.end was all mushroomed,I took off an additional 1/8'',put it back together,everything seems good now

I just got done puting my bellhousing on my 460 and bolting on the starter to make sure it all works. Here is a list of the parts I have used so far: Engine-1977 460 out of a van style motor home, flywheel-19?? 390 drilled to accept clutch assembly off 1978 400 (12" clutch), stock 400 bellhousing, starter- 1977 460 automatic, pilot bearing-1978 400, rear engine plate (between block and bellhousing)-1978 400 (had to trim center to fit around 460 crank flange. So far, it all fits together without clearance problems. FYI this flywheel setup sticks out about 1/4" farther from the back side of the block than the one on my 400. I hooked a battery to the starter and it spins the engine well without any evidence of binding or excessive pinion to ring gear backlash. The stock 400 flywheel had 180 teeth and the 390 flywheel has 184 teeth. If you are using a flywheel off a newer (external balance) 460 you need to get a zero balance flywheel or have the couterweight machined off your flywheel and have it balanced. So far so good on my project. By the way- I am putting this engine in a 78 F250 4x4 SC that cam with a 400. I would appreciate any suggestions, since I have been figuring this all out as I go.

It sounds like you have a good handle on it so far. What did you decide to use in the motor mount department? Have you checked the fitment of your exhaust manifolds yet? the passenger side might be an issue (I know cars ones are, not sure if vans were or not) One thing to check, does your clutch disengage when you push it in? Something to check before you got it all put together. I used a bare block, crank bearings, and the crank to test it all.

am swapping 73 lincoln w/auto into 75 f250 4x4. am changing to 4spd. already have a 400 bell. am using a 390 flywheel (internally balanced). am concerned as to how big a clutch to use-11" or 12"-will an 11" be good enough for medium+duty. if not, i could get the flywheel drilled to accomodate 12". also have been told that spacing could be a problem and have heard this can be cured by using the proper pilot bearing (i think it should be the one for the 400 application) otherwise something about the trans spline or sleeve jams up and leaves a 3/8" gap between bell and motor. i have removed the entire front end of the truck exposing the frame so everything is easy to get to. thanks MM

a 12" clutch will need the casting ribs trimmed on the upper inside of the belhousing. This thread answers all of the questions you have. If you have a bare block with a crank laying around, use it to mock up your transmission.

Ran into this problem before. Same situation. The clutch fork bracket was hitting the pressure plate. with 2500lb, 12" pressure plate it had the three arms in center in pressure plate where bearing rides. Would not work at all and I tried several things. Later I went to a centerforce dual friction clutch and it clears and has better pedal pressure than stock clutch and when turning rpm's it clamps harder, great set up. Ran this setup for several years and broke everything behind this centerforce. It hooks hard with nice big block up front. Did the L@L kit system with 40lb flywheel 12" clutch and headers with motormounts. I have broke a set of motor mounts before.

Can I solve all of this clearance problem by using an 11" clutch instead of a 12"? Would the smaller clutch cause that much performance concern if this truck is not expected to really get into any real "digging", only plan on pulling a medium soze horse trailer on fairly good roads. Thanks. MM