Flexplate application question

[yellercat]

First 390 is on the floor and going into a 69' F250 with a C-6.

Have ordered new flywheel bolts and did not disassemble either the engine (or the truck), so the simple question is whether a reinforcement ring is required with the flexplate?

Presuming also that threadlocker and no washers is appropriate. All comments appreciated. Really 

[GerryP]

Yes, the ring is a critical component.  You may experience stress fractures in the plate holes without the ring.  Threadlocker is recommended.

[HarleyJack17]

X2 what Gerry said. 

[yellercat]

Thought that might be the case, thank you.
 Bot the engine apart so tho I got a bellhousing and flywheel, there was no reinforcement ring for the flexplate.
Thanks Gents!

[hwoods]

what is part # for the reinforcement ring?  I think I need to get one as well

[Rory428]

Actually, in the early 80s I worked at a production engine shop, installing the new engines in customers vehicles, and at that time we did quite a few 360 & 390 Ford PU trucks, as well as some 330/361/391 FTs in cab overs, Louisvilles and 5 ton style F series trucks. I did several 75 &76  Ford pickups, and was suprised to see that there was new reinforcement ring for the flexplate bolts, and the bolts themselves were a bit shorter. So perhaps, towards the end of FE production, they stopped installing the rings? I do know that I seen enough of them that it was unlikely that there were this many that had the rings removed during say a transmission rebuild.

[thatdarncat]

what is part # for the reinforcement ring?  I think I need to get one as well

The Ford part number is B9AZ-6A366-B. That was for a package of 3, which is how Ford serviced them at the end. Slight chance you might find one at your Ford dealer if they didn’t use up their package of 3. The same reinforcement ring also was used on MEL engines and early 429/460’s. If you search that part number on EBay you can usually turn up some originals.

[GerryP]

...So perhaps, towards the end of FE production, they stopped installing the rings? ...

They did.  In the early '70s is what I recall reading historical literature.  I know when Ford quit using the ring, they spec'd a shorter flywheel bolt.  So, if you don't use the ring but are reusing the factory bolts, just something to keep in mind.  So, you have them dropping the ring and a shorter bolt.  What I don't know is if there was a material change in the flywheel so that the ring wouldn't be necessary, or if they just said "screw it, we can save one penny if we dump the ring."

And this ring thing isn't just an FE thing.  All Ford products with an automatic used the ring.  It might be easier to understand this by researching the ring for the smallblocks. 

Unless it's a later application, I believe the ring is necessary since the bolts don't use a washer and, again, I don't know why they stopped using it.  I don't think you'd die and go to hell if you didn't use one, but you never know.  They must have had some fractures in testing, so along came the ring.

[hwoods]

I have a Performance Automotive flex plate, does it need the reinforcement ring?  Always ran a top loader previously, so I have never ran into this before    Thanks

[GerryP]

I have a Performance Automotive flex plate, does it need the reinforcement ring?

No.  Strictly a factory Ford specification.

[blykins]

Make sure that whatever combination you end up with doesn't get the flexplate bolts into the rear main cap.   Some bolts are too long.  Takes thrust bearings out in a heart beat.

[FElony]

So factory CJ's with the wagon wheel pie wedge whatever flexplates are supposed to have rings, as they are not solid and maybe weaker than the typical?

[FElony]

So factory CJ's with the wagon wheel pie wedge whatever flexplates are supposed to have rings, as they are not solid and maybe weaker than the typical?

OK, I went over to Mr. Hollenbeck's site and yes, the B9 ring is stock. I bought out a large stash a dozen years ago or so and there were a half dozen wagon wheels, but I cannot remember any rings. Dagnabbit. Boxes of misc stuff so maybe I better dig.  https://www.428cobrajet.org/id-flywheel-auto

[thatdarncat]

Yes, I just double checked the Ford Parts books - that reinforcement ring is listed for all the car FE’s with automatics from ‘58 to the end of car FE production, including all 428’s and the ‘68 427 w/automatic. It’s even listed for the 330/361/391 FT with certain automatic transmissions. For 352/360/390 pickups it’s listed through the 1973 model year, it’s not listed for the ‘74-‘76 pickup FE’s.

[FElony]

So factory CJ's with the wagon wheel pie wedge whatever flexplates are supposed to have rings, as they are not solid and maybe weaker than the typical?

OK, I went over to Mr. Hollenbeck's site and yes, the B9 ring is stock. I bought out a large stash a dozen years ago or so and there were a half dozen wagon wheels, but I cannot remember any rings. Dagnabbit. Boxes of misc stuff so maybe I better dig.  https://www.428cobrajet.org/id-flywheel-auto

So, FElony, the next logical question: was the CJ/SCJ the only engine that had these flexes, and did Ford engineers think the couple of pounds of reduced rotating weight was going to make a smidge more power?

Um, FElony, that's two questions.

Hard to shut the brain off, FElony. You should know best.

Yes, I certainly understand, FElony. More than you think. More...than...you...think.