what size flywheel
Thread Starter
Melting Slicks
Joined: Jun 2004
Posts: 2,077
Likes: 0
From: westmoreland N.H.
what size flywheel
how do i tell if i have a 153 tooth ,or a 168 tooth flywheel. i have a 1970 350/350 with a four speed. looking to go with an aluminum flywheel. the fidanza one..
would like to do this without taking off tranny.
would like to do this without taking off tranny.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I'm 99% sure that all Non-bigblock GM cars came with 153 tooth.
I've always changed mine over to 168 to make the starting easier. you can also use the bigger 11 inch clutches with a 168 tooth. They last longer and have more holding power.
mini Starters are relatively cheap. The GM model made by Nippon denso(SP?) is a very good starter.
I've always changed mine over to 168 to make the starting easier. you can also use the bigger 11 inch clutches with a 168 tooth. They last longer and have more holding power.
mini Starters are relatively cheap. The GM model made by Nippon denso(SP?) is a very good starter.
Drifting
Joined: Sep 2006
Posts: 1,259
Likes: 2
From: MS
If original, it will be the 168 tooth as the only Vette in 70 that used the 153 tooth flywheel was the ZR-1; all other 4-spds used the 168 tooth.
Look for number 3899621 cast into your bellhousing, if you see it this is the 621 bellhousing and it was only used with the 168 tooth.
The 68 small blocks I believe used the 153 tooth, so did the L88, ZL1, ZR1 and the 1978 L48; all others should be the 168.
Usually the 403 bellhousing with the 153 and 621 with the 168.
Look for number 3899621 cast into your bellhousing, if you see it this is the 621 bellhousing and it was only used with the 168 tooth.
The 68 small blocks I believe used the 153 tooth, so did the L88, ZL1, ZR1 and the 1978 L48; all others should be the 168.
Usually the 403 bellhousing with the 153 and 621 with the 168.
Last edited by wfo76; Jul 9, 2008 at 03:30 PM.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
If original, it will be the 168 tooth as the only Vette in 70 that used the 153 tooth flywheel was the ZR-1; all other 4-spds used the 168 tooth.
Look for number 3899621 cast into your bellhousing, if you see it this is the 621 bellhousing and it was only used with the 168 tooth.
The 68 small blocks I believe used the 153 tooth, so did the L88, ZL1, ZR1 and the 1978 L48; all others should be the 168.
Usually the 403 bellhousing with the 153 and 621 with the 168.
Look for number 3899621 cast into your bellhousing, if you see it this is the 621 bellhousing and it was only used with the 168 tooth.
The 68 small blocks I believe used the 153 tooth, so did the L88, ZL1, ZR1 and the 1978 L48; all others should be the 168.
Usually the 403 bellhousing with the 153 and 621 with the 168.
I have not worked on many of the older Vettes
Burning Brakes
Joined: Oct 2007
Posts: 816
Likes: 107
I am running a 168 tooth 11" on my small block it helps out a ton with 4-speed launches. I am going to an aluminum flywheel also but have not made up my mind on which one. Hayes has one for $379 I went to Fidanza's site and I must have been doing something wrong because I could not find anythin other than import stuff?????
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I am running a 168 tooth 11" on my small block it helps out a ton with 4-speed launches. I am going to an aluminum flywheel also but have not made up my mind on which one. Hayes has one for $379 I went to Fidanza's site and I must have been doing something wrong because I could not find anythin other than import stuff?????
Try here. It does list wheels for GM
It is a PDF file and down at the bottom go to the flywheel section.
http://www.fidanza.com/files/Fidanza06_07appguide.xls
Burning Brakes
Joined: Oct 2007
Posts: 816
Likes: 107
Try here. It does list wheels for GM
It is a PDF file and down at the bottom go to the flywheel section.
http://www.fidanza.com/files/Fidanza06_07appguide.xls
It is a PDF file and down at the bottom go to the flywheel section.
http://www.fidanza.com/files/Fidanza06_07appguide.xls
I called the dealer last week, I think it was you who suggested the L88 Flywheel, they only had a listing for a 10" and I run an 11" I probably would go with a 10" if I had to but a clutch assembly to but mine is still in good shape just want to ligthen up the rotating mass a little.
Thanks again
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Thanks now I have a part number I can call and get a price
I called the dealer last week, I think it was you who suggested the L88 Flywheel, they only had a listing for a 10" and I run an 11" I probably would go with a 10" if I had to but a clutch assembly to but mine is still in good shape just want to ligthen up the rotating mass a little.
Thanks again
I called the dealer last week, I think it was you who suggested the L88 Flywheel, they only had a listing for a 10" and I run an 11" I probably would go with a 10" if I had to but a clutch assembly to but mine is still in good shape just want to ligthen up the rotating mass a little.
Thanks again
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Yes they did but the clutch surface area was smaller. They used a dual disc on the small diameter flywheels for high winding performance motors.
