Hot Rods Help...desperate for Ford Flexplate answers

Ok well I jumped the gun ordering part to get my car back together. I’ve got a C4 going to a 289...no big deal....here’s where it gets weird..went to bolt the converter up and it’s 10.5 bolt pattern..my Flexplate’s 11.5....and now for the weird part...it’s a 168 tooth...I’m lost..can’t find 168 flex plate, let alone one with 10.5 bolt pattern...closest I can get is a 164..what would I do for a stater? Anyone come across this before? Really bummed out..not fun pulling everything back out and going back to square one.

 

To the best of my understanding and experience, small block Ford flex plates are either 157 or 164 tooth........I have never seen or heard of a 168 tooth Ford small block flex plate. I am thinking you need a 157 if you have an early C4 for your 289. Also, there is the 'imbalance' weight to consider. A 289 would have a 28 ounce weight.

Ray

 

The 168 tooth flexplate was superceded by the 164 tooth, sometime in 1968. The 168 will probably have a C5 part number on it, and was used from 1965 to 1968, I think.

 

As long as they are both the same diameters there should be no problem. I've adapted them to even fit the six cylinder 200/250 engine, which is supposed to use a torque converter which has the ring gear on it. Didn't have one, but had a flexplate for a v8....

 

http://www.pioneerautoinc.com/catalogs/ look in there flexplate catalog some good info in there in the back pages also some specs. looks like 168 and 164 are only .016 off in diameter. same pitch

 

here is some ring gear specs

 

The transmission determines which ring gear and block plate is used. If you have a case fill c4 with the 10.5 converter you need a 157 ring gear AND block plate. If you have a pan fill trans you need a 164 ring gear and block plate. The block plates are not the same! The starter is in a slightly different spot. Use any sbf automatic starter.

 

Can read it better BIG

 

Yeah, don't think for a minute that you can leave the block plate off and have a happy transmission, not for long

 

Thanks Guys Anything else?

 

So if I put a 164 tooth flex plate, with the proper weight, and a correct starter do you think it would work? This is holding me up from getting my car on the road before the snow flys here

 

Did any c6 use a 157 tooth flywheel

 

Where does a C6 fit in this discussion? OP says he has a C4 trans. Does not say if it is 'case fill' or 'pan fill'.

 

I do not have first hand knowledge, but from what I have read and been told, yes, you can use the 164 tooth flexplate.

 

I’m starting over today...looks like 50 oz balancers came on 302. My motor is a 289, trans is a early C4, looks like a later bell housing..289 never had a 50 oz balancer...so confused.. think it’s time to start from scratch from the dampener back

 

Pan fill

 

260, 289, 302 and 351 windsor all had 28 oz imbalance till 1981, then the 302 went to 50 oz. The 351 Windsor stayed 28 oz throughout.. Your 289 should have a 3 bolt crank pulley harmonic balancer which for the most part would be for 28 oz. Get the proper flywheel and block plate and you're good to go. No need to really start over. I would assume your 289 is a 6 bolt motor and not the early 5 bolt one. Makes no difference in imbalance but the 5 bolt bellhousing stuff is getting harder to find....especially in a c4.

 

Do you have pictures of the bellhousing on the transmission? That will tell you if you use the 157 or the 164 tooth. Bellhousings are removable. I had an early 289 with 5 bolt c4 with 157 tooth flex plate, I swapped in early 302 with 6 bolt, found a 6 bolt c4 bellhousing that required a 164 tooth flexplate.
Yes, there was a lot mix and matching, but instead of seeing it as a bad thing, see it as you have a lot of options of getting factory made readily available parts, as long as you know the differences.

 

Looks like the later 164 tooth to me. So, you need 164 tooth, 28oz with 10.5" bolt circle for converter. I don't know an application off the top of my head, but that info should get you in right direction.

Do you have a block plate? It needs to match the bellhousing. You can just lay it on top to check if it matches. The starter bolt holes are what your looking at. I have some loose plates I can look through if your needing one

 

Good info here
http://www.pigseye.com/sadie/trans/c4.htm

 

Couple that look like they may work

https://www.ebay.com/itm/PRW-Flexpl...z-EXT-SFI-29-1-Chromoly-for-Ford/352193681850

https://www.summitracing.com/parts/pqx-1830211/

 

Awesome guys.. yeah the block plate on there worked with the 168 tooth, it was all together before I re did the motor. I just gotta verify the dampener weight and order the 164 tooth I guess.

Problem stemmed from me ordering a 10.5 bolt pattern converter and filing it with fluid..I assumed I got it right..and so did Jegs haha... well it’s cheaper to buy a flex plate and maybe a starter then another converter.

 

The summit one says small bell..I thought mine was a big bell housing...arghhh

 

Hnstray, I have a friend that asked me

 

Terminology can be confusing. Calling a trans a 'small bell' vs another that is a 'big bell' usually means what engine series they are designed to fit....for instance, in Fords there are C4 trannies that were used with engines that have a different (larger) block bolt pattern than the 'small block Ford' series.

Now were it could get confusing is the discussion here about C4's and the use of either 157 or 164 flexplates and corresponding converters of different diameters. However, the bell housing bolt pattern of both are the same. They differ in starter location and block plate used with the respective bell housings.

So, be careful in making assumptions about what Summit means and/or how you are categorizing your particular trans case.

Ray

 

Honestly, I had never seen C4 bellhousings refereed to as big or small before today, only 157 or 164 tooth. I'd probably ignore that part, order it and try it out before dropping the whole thing in.
For what it's worth, in my stack of small block Ford flexplates I have 157, 160, 164, and 168 tooth flavors, with Ford stampings and mid 60s parts numbers. The 160 is same diameter as 157, and the 168 is same as 164. Not sure why the difference, different applications or whatever. I don't have any with the combination you need. Seems like the standard converter bolt pattern for the 164 tooth bellhousing is the larger 11.5" one. But since the small block Fords and C4s are so popular with the Mustang crowd, the aftermarket can provide what the factory didn't.

 

Out of left field, the only C4 I heard of being a "small bell" was the one behind the 302 in a Mustang II. I had one, it really was smaller than the normal bell and had a smaller TC and ring gear. Like the front suspensions, they went into a bunch of 70's era rods because they fit under the floorboard a little better. Good luck finding one of those now.

 

Maybe that was a C3?...........

 

Nope; C4. Limited production run since V8's were only available from 75-78 in MII's. 4cyls and V6's got C3's. The actual transmission section was the same as any other case fill C4. Just the bell, TC, and flex plate were smaller. Sharper angle down to the body of the trans, less "bell" to it. BTW C3's are simplified C4's, not a bad trans, just not strong enough to take a v8. Can't recall right away what was special about the C5's.