BuffaloBILL

Hey gang
I recently posted this question on the C2 Forum by mistake
Any advice would be greatly appreciated I screwed up on 153 Tooth Flywheel choice
Needs Advice
I ordered a 153 Tooth Flywheel for my 70 Vert 350 SBC It originally came
With a 168 tooth flywheel but got a good deal on a 153 tooth with a new clutch kit everything bolted up fine However after placing my new starter the pinion gear is fine going to the flywheel however it's about 1/2 inch gap "Under" the teeth of the 153 Tooth Flywheel I have tried 6 153 tooth Starters to no avail. I understand that I needed to go to a 153 tooth starter but I fear that all is lost and have to remove the 153 Tooth Flywheel and replace it with a 168 tooth 14 inch flywheel Unless someone can suggest a starter
I hate to go thru all this work again it has the bigger Bell Housing like the 1 on the right in the photo
Thanks
Bill
twOTE=DZAUTO;1575260851]There is no such thing as a 10.5 or 11in flywheel.
Beginning with the very first Chevy V8 in 1955, there have only been two sizes of flywheels/flexplates:
1. Small, 12 3/4in diameter (frequently referred to as 13in) with 153 teeth.
2. Large, 14in diameter with 168 teeth.

The early flywheels were ONLY the large, 168 teeth version and MOST of them only had a bolt pattern for a 10in clutch (later replacement clutches are now about 10.5in). Some of the early 168 teeth flywheels, such as those for trucks had a bolt pattern for the 11in clutch.
In 1963, the smaller, 153 teeth flywheel was introduced and it ONLY accepted a 10.5 clutch.
The later, 168 teeth flywheels had a bolt pattern for the 11in clutch.
SOME replacement 168 teeth flywheels had a dual bolt pattern for either the 10.5 or 11in clutch.
ALLLLLLLLLLLLLLLLLLL V8 Chevy flywheels for engines with a 2-piece rear main seal have the same bolt pattern for the crankshaft. And ALL V8 flywheels, EXCEPT those for the SB400 and 454 BB, are neutral balance. The SB400 and 454 use the same size 168 teeth flywheels and accept the same 11in clutch, but they have an additional weight on the front side of the flywheel for engine balancing purposes. These 400/454 flywheels are commonly referred to as External balance flywheels.

Here is a comparison of the 168 teeth neutral and external balance flywheels.


Here is a comparison of the 153 teeth and a 168 teeth flywheels.


Now, this throws one more fly into the ointment. Depending on which flywheel you choose, you must also have the correct corrosponding size bell housing.
Here is a comparrison of the small and large bell housings.

suprspooky

I'm a little confused with your question but here's what I know. The Starter location is based on holes in the Block (BBC/SBC) which are the same in relation to crank center and there are two types of bolt arrangements in the Stater Nose Housing that determine the gear mesh (hole position in the Nose Housing moves the starter closer or further from the Ring Gear), Bendix tooth count is the same. Ring Gear Tooth Pitch is the same (bigger dia. Flywheel/Flex =168, smaller =153) they just move the Starter Bolt holes in the Nose Housing. This only applies if your Starter bolts to the Block (after 1962 I think?)

Jebbysan

An aftermarket starter will have two sets of bolt holes in it to accommodate both 153 and 168 tooth flywheels......

I have been using these for ten years now and they are IMHO the best on the market......

https://www.summitracing.com/parts/cvs-5323

Jebby

Dirty Dalton

According to Chev Power book:

Flywheel - 3991406
Starter - 1108381
It also lists bolts, but I don't know if they are different from the 168 tooth starter. If you need them, I have the P/N.

You also need the correct 'inspection plate'. I thought that was listed in the Chevrolet Power book, but I can't find it. The bell housing is also different. P/N 3858403, I believe.

BuffaloBILL

Hello
Thanks for your reply
I will try to clarify my question
My original block has 3 mounting holes that will work on both the Stagered mounting 168 tooth starters as well as the "4" hole 153 tooth high torque starters.
Both The 168/153 reach the correct distance to operate the flywheel Where they fail is that they fail to "Mesh" to the flywheel there is about a 1/2 inch gap Under the teeth I measured the ordinal Flywheel it's 14 inches where the 153 tooth Flywheel is in the car but a rough measurement is 11-12 inches. The reason I did not use the ordinal 14 inch 168 tooth flywheel when I rebuilt the engine was because there were areas in the ring gear that had worn teeth If there is a high torque starter out ther it would save me the work the remove and replace the flywheel.
Side note I spoke to Summit Racing Tech line staff several occasions and purchased 3 of there recommended statrters to no avail
I am now rethinking that the Flywheel itself is not the correct application even though they say that it is for a SBC (350)Corvette
Frustrated
Bill
QUOTE=suprspooky;1593605865]I'm a little confused with your question but here's what I know. The Starter location is based on holes in the Block (BBC/SBC) which are the same in relation to crank center and there are two types of bolt arrangements in the Stater Nose Housing that determine the gear mesh (hole position in the Nose Housing moves the starter closer or further from the Ring Gear), Bendix tooth count is the same. Ring Gear Tooth Pitch is the same (bigger dia. Flywheel/Flex =168, smaller =153) they just move the Starter Bolt holes in the Nose Housing. This only applies if your Starter bolts to the Block (after 1962 I think?)[/QUOTE]

Dirty Dalton

For some reason I can't edit my above post...

Inspection Plate cover P/N 354497 (According to Paragon)

Jebbysan's solution may simplify and eliminate need for different bellhousing and inspection plate.

Dirty Dalton

Who is 'they'? Does the P/N jive with the one I listed from the Chevy Power Book? Is the starter the equiv of the one I listed?

This is very curious.

BuffaloBILL

I am embarrassed to say Summit part number purchased throu a different vendor on Amazon

QUOTE=Ed Harrow;1593606823]Who is 'they'? Does the P/N jive with the one I listed from the Chevy Power Book? Is the starter the equiv of the one I listed?

This is very curious.[/QUOTE]

gg521

I run a 153 tooth flywheel on a 350 block. Jebby's solution will work but there are several other starters that will accomplish the same thing. If you look at the picture of the starter, you will see that there are different mounting holes on the starter. This will take up the clearance that you are referring to.

Jebbysan

There are many aftermarket starters that have similar mounting holes drilled in them.......I just like this starter as it is bulletproof...reasonably priced and you can clock it to clear Vette headers and keep any of the unit 1/4" away from heat......I would run nothing else on my 72'. I had one on my 66' too.....I am a stickler for a strong starter and a high power ignition to start up anywhere, anytime......

Early Nova's came with 153 flywheels.....but I believe the starter had a staggered bolt pattern......

Jebby

lionelhutz

Link or post the part numbers for the starters you purchased.

lvmyvt76

probly just a different nose piece is need on his current starter. find a starter rebuild shop and talk to them, they may even have the part, should not cost over $10 IMO

rklessdriver

Any of these starters will work for a 153 tooth SBC.

https://www.summitracing.com/search/...y=DisplayPrice

I ran a Powermaster 9000 on my race car. It's a good starter.
Will

stingr69

Sorry if this was already posted....you can not mix and match starters flywheels and bell housings period! They ONLY work as a complete team. The hole in the bell housing will ONLY accept a starter in ONE location and that particular location will only work with ONE size flywheel. YOU HAVE TO MATCH FLYWHEEL, BELLHOUSING, AND A STARTER THAT WILL BOLT UP. Blocks may be drilled for different starters but the bell housing will never work with any other flywheel or nose cone location. Been there, done that.

Big bell housing requires the bigger flywheel and a compatible starter nose cone.

Small flywheel requires small bell housing and compatible starter nose cone.

and the starter brace is different too.

It is all or nothing. :~)

rklessdriver

Only when you try to use factory type starters.... when you use an aftermarket mini starter.... there is no nose cone and no brace. Everything is compatible with everything else.
Will

Jebbysan

This is true.....so the OP should have his answer now on what to use

Jebby

Tampa Jerry

I know this is a pain to do, but why not use your original flywheel. You can buy a the correct ring gear for $20 and a machine shop can install it for a few dollars. If you have a torch, you can do the install yourself. If you use a machine shop, they can install the gear, resurface the flywheel and balance the pressure plate as an assembly. A NAPA machine shop can do all of this in under an hour. Jerry

stingr69

Mini starters have dual bolt patterns and many blocks have dual bolt patterns but that is not the issue at all. The BELL HOUSING does not have dual openings. it only has one and it is set for ONLY ONE crankshaft to starter centerline to centerline distance. that distance is half the diameter of the ring gear.

The bell housing WILL NOT accept any other starter centerline distance from the crankshaft centerline.

Small bell housing = small flywheel
Big bell housing = big flywheel

I know what you are thinking - The small flywheel will physically fit inside a large bell housing BUT that larger bell housing will only accept a starter nose cone POSITION designed to fit the BIGGER FLYWHEEL. Aftermarket starters will bolt up to engines with dual bolt patterns but the bellhousing nose OPENING will only accommodate ONE of those two starter/block bolt patterns and the one it will bolt up to will put the starter to crank distance too far away to allow the teeth to engage. Starter will be too far away from the ring gear teeth if you have a small flywheel in a big bell housing.

The OP needs to ditch the "621" bell housing and find a "403" smaller bell housing and the GM starter for the smaller flywheel setup will fall together (or aftermarket mini starter)

The "621" bell housing will sell for more while the "403" will be cheaper to buy so he could pick up a few bucks there.

Alternately he could obtain the larger flywheel designed to accept his smaller clutch assembly and he will be good to go with that.

BuffaloBILL

Sorry for the late response had to go out of town But I believe you are correct I was hoping to have better news now i need to think about a Belhousing purchase of bite the bullet and remove the 153 Flywheel I think removing the tranny and Bell housing would be easier than going thru the whole assembly Tranny Pressure Plate Clutch ect.

suprspooky

Thanks for getting all of us on the right page, I just had it in my head he had the wrong Starter, never paused to consider that he was mixing and matching