427 and 350 flywheels....any difference?

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Apr 9, 2007 | 01:25 AM

vintage-racer

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From: michigantown IN.

427 and 350 flywheels....any difference?

I ve been chasing a long term demon with my 69 coupe.When I hit the key the starter seems to hit HARD and yet doesn't turn my mild small block over very quickly. It almost seems like there is too much wear on the ring gear and so when the starter begins to turn the flywheel it actually Bangs(not grinding) teeth to teeth initially No amount of shimming has made any difference. When I replaced my clutch last winter I also replaced the starter.Imagine my surprise when I hit the key and heard that same hideous sound.The only thing unchanged is my flywheel which turns out to be a 68 bigblock unit #3789733 and looks to be in fairly good condition. I'm about to replace it with an Advance auto unit FW 100,which supposed to be a standard GM replacement, as I can no longer listen to this percussion. I wind up parking my beautiful Stingray in the back of the lot everywhere I go from embarassment.Pardon my french...but it's like seeing a super model walk past and she farts LOUD. Unless I can come up with anyother solution I'm ordering the new flywheel soon.

Last edited by vintage-racer; Dec 24, 2011 at 01:37 PM.

Apr 9, 2007 | 01:52 AM

Twin_Turbo

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apart from gear teeth# (and diameter) they are the same, the only diff is ext /int balance. Only the 400, aftermarket stroker setups and the 454 are ext. balanced. All small blocks apart from the 400 and the 427 (and 396) are internally balanced. We are talking about a flywheel right not a flexplate?

Last edited by Twin_Turbo; Apr 9, 2007 at 03:08 AM.

Apr 9, 2007 | 08:21 AM

bashcraft

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From: Butler Pa

I recently installed a BB im my car and used the original SB flywheel with no problems.

Apr 9, 2007 | 08:49 AM

Ironcross

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From: Taylor Michigan

You do not need a flywheel, all you need a 20.00 ring gear. One can pop the old one off and the new on in 10 minutes with the flywheel on a bench. You will need SOME heat to get the new one on {torch}

Apr 9, 2007 | 12:25 PM

vintage-racer

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From: michigantown IN.

ring gear replacement?

I've heard of guys putting the flywheel in the freezer and heating the new gear for install .How do you get the old one removed,and the new pressed into place? In looking at my flywheel and i don't see where the ring gear ends and the flywheel begins.I also didn't know if part of my problem was that a BB flywheel might have a different (back)spacing for starter engagement? are all gm flywheels diminsionally identical if they have the same # of teeth?..........Sorry for so many ?'s , but I know you guys are the ones with the all the answers

, I'm all ears.

Last edited by vintage-racer; Dec 24, 2011 at 01:38 PM.

Apr 9, 2007 | 01:07 PM

Ironcross

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From: Taylor Michigan

It`s relatively simple. A chizle and big hammer will knock it off and it will only come off one side. Buy the ring gear and you will see how and which side it`s removed from. There is a flange that it seats against. Set the gear on the flywheel after its heated. Fortunately you will not hurt anything so dont be afraid. The heat will expand the gear and drop it on.....

Both BB and SB use the same wheel. Just count the teeth to make sure.

May 27, 2007 | 12:22 AM

vintage-racer

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From: michigantown IN.

how sweet the sound

I finished reinstallng the motor this evening after replacing my flywheel ring gear and was pleasantly surprised to hear a quiet and quicker starter engagement. Thanks guys for the advice on not replacing the whole flywheel. The ring gear install could not have been easier. No more hiding my beautiful Stingray in the back of the lot.