I'm new here and trying find answers to swap my 400 for a 460 in my 78 F-250 4x4. I have a NP435 trans and am having trouble with the flwheel. I've read that a 390 one will work but I cant find one with 180 teeth. I've seen the 460 one's at Jeff and L&L but don't want to spend $385 and then buy their clutch to fit it. Any help wil be greatly appriciated.

 

Is your 460 internal balanced or external balanced ?

 

It's an early 70's internaly balanaced motor. I have read that a 390 flywheel will work do to it's neutral balance and retain my 400 starter but all the 390 flywheels i see are 184 tooth 15 1/2" diameter. My 400 is also 15 1/2" but has 180 teeth. Wont this consantly eat my starter.

 

I think it will eat your starter but how long it will take is the question. So many times something will work but not necessarily work right. I just finished rebuilding the 460 (72 Lincoln) in my 77 F250 4X4 which has an NP435 transmission. Someone else had done the conversion from a 351M in years past. The ring gear on the flywheel had failed-there were multi-tooth flat spots and nowhere on the ring gear had the starter drive teeth engaged as much of the ring gear teeth as they should have. I do not know what that flywheel/ring gear was designed for but it certainly was not correct.

I did some research and, along the way I, too, heard that a 390 flywheel would work but, the tooth count on the ring gear was 184.The Ford Racing Parts Catalog shows a Flywheel for a manual transmissioned 1968-78 460 PN: M-6375-Z460B with a suggested list price of $309.95. The tooth count is 176. The listing says the flywheel will work with a 11', 11.5", or a 12" diaphragm style clutch.

The L&L fllywheel also has 176 teeth on the ring gear. I really didn't want to spend almost $600 for the L&L flywheel, clutch disc, and pressure plate but, in the end that is what I did because the set was specifically designed for my application. I still had to grind some off of the faces of the 4 bosses(bumps) in the flywheel housing so the ring gear teeth would clear them.

 

I don't know just why no one will cast a internal balance flywheel for the 460. I checked everywhere before I bought the billit Ford flywheel but in the end it was worth it. It takes any size clutch and any style of psi plate but the $300 was a little hard to swallow.

 

I've done some more research and it looks like I can use the 9 tooth bedix gear ot of a 390 starter in my 400 starter. It appears the 390 starter will fit but has larger body than the 400 starter and creates clearance issues with the exhaust on gets hot and fries so I would still be buying starters frequently. I plan on running 3/4 headers from Jeffs and 3" exhuast. Do you know if that will give me clearance for a 390 starter or is it possible to put the 390 9 tooth bendix in my 400 starter. Also I see I can get an 11 1/2" diaphram style clutch for the 390, will this fit or will I need to grind?

 

I don't know the answers to your questions but, I'll bet some one else does.

When I was researching parts for my 77 F250, there seemed to be a lot of conflicting information. When I pulled the 460 out of mine for the rebuild I noticed sime things I did not like.

The stock 351m/400 bellhousing and clutch release lever had been used. However, there was evidence that the clutch pressure plate had rubbed on the lever. I suppose that is why someone used a 1/4" spacer between the engine plate and the bellhousing and also between the plate at the starter and the bellhousing. That spacer was enough that the alignment dowels between the engine and the bellhousing were not doing their job.

The starter which was in it was for a 1977 460 (that starter fits several applications) but with the too small, incorrect tooth count flywheel, the ring gear teeth "had the job done to it." During the almost 2 years I had the truck before the ring gear went bad, the starter never did sound just right.

As I said earlier, I just decided to end my headache and buy the L&L conversion clutch/flywheel set and use the 351m/400 bellhousing and eliminate the spacer. But, even then, I had to grind some material off the 4 bosses in the bellhousing to clear the flywheel.

Good luck!

 

Thanks for the info. I think I'll pull my bell housing and mock everything up so I can look inside and see before I install it in my truck. I'll get back with what I come up with in a week or two.

 

D6PZ-11350-B (replaced C6VY-11350-A & C4DZ-11350-A) .. Starter Drive (Motorcraft SD302).

Applications 1964 and later: 260/289/302/351C/351M/351W/352/360/390/400/410/427/428/429/460 / 1963 and earlier V8's used a Bendix inertia drive.
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All 460's from 1968 thru 1982 came with a C6. 1983 was the first year for M/T & 4WD (F250/350 only).

351M uses a different flywheel (D7TZ-6375-E) than a 400 (D7TZ-6375-D). 351M uses an 11" clutch, 400 uses a 12" clutch.

The difference between 1965/76 352/360 (C5AZ-6375-K) & 390 (C5AZ-6375-L) flywheels: 352/360 uses an 11" clutch on a 12 3/8" bolt circle, 390's use an 11 1/2" clutch on a 12 7/8" bolt circle.

ALL 1965/76 FE flywheels have 184 teeth / 1958/64 FE flywheels have 148 teeth.

1970/76 360/390; 1977/78 351M/400 and 1979 351M/400 before serial number DG0,001 use the same clutch fork (DOTZ-7515-A).

1979 from serial number DG0,001, 1980/82: 351M uses a different clutch fork (D9TZ-7515-A) than a 400 (D9TZ-7515-B).
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Ford changed the 460 engine mid-model year 1979 .. has a weighted spacer. The block casting number is D9TE-AB

The flexplate and balancer are different than the previous 1968/70 C8VE/C9VE/DOVE and 1971/79 DIVE-AB blocks that do not have a weighted spacer.

This was a "running assembly plant changeover" so there are no 1979 before/from serial numbers or production dates. Does not affect Passenger Cars, 460's were not installed after 1978.

 

My 390 flywheel had holes for both size clutches.

 

Autoparts store gypo "fitz-all" .. not genuine Ford parts. As original:

1965/67 Passenger Car 352 & 1965/71 390 / 1965/67 F100/350 352 & 1968/76 360/390:

C5AZ-6375-K .. 352/360 Flywheel / (6) 5/16" -18 pressure plate attaching holes on a 12 3/8" bolt circle-Use with 11" clutch.

C5AZ-6375-L .. 390 Flywheel / (6) 5/16" -18 pressure plate attaching holes on a 12 7/8" bolt circle-Use with 11 1/2" clutch.

 

It's good to have NumberDummy on the site to keep us staright on Ford parts! Thank you. I did use the 77/78 351M/400 clutch fork (D0TZ 7515-A) clutch fork.