327 Flywheel
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 1,062
Likes: 10
From: Dallas TX
327 Flywheel
What were the specs on a 63 340hp flywheel? 153 tooth? PN 3791021?
I am looking for a good used one or a reasonable replacement. Machine shop wants the flywheel to balance the 327 build that I am working on. Original flywheel (I hope) is on the NOM that is in my current driver.
Any thoughts on tracking one down?
I am looking for a good used one or a reasonable replacement. Machine shop wants the flywheel to balance the 327 build that I am working on. Original flywheel (I hope) is on the NOM that is in my current driver.
Any thoughts on tracking one down?
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
Any Chevy II four, six or eight cylinder from '62-'67.
Any Chevelle six or eight cylinder from '64-??
Pass car, the same way.
Corvette '63-'??
In other words, there were tens of millions made. Don't be bashful.
Why does the machine shop need a flywheel to balance the rest of your rotating assembly? They should be able to balance without it.
Any Chevelle six or eight cylinder from '64-??
Pass car, the same way.
Corvette '63-'??
In other words, there were tens of millions made. Don't be bashful.
Why does the machine shop need a flywheel to balance the rest of your rotating assembly? They should be able to balance without it.
Thread Starter
Burning Brakes
Joined: Jun 2007
Posts: 1,062
Likes: 10
From: Dallas TX
Not sure why he wanted the flywheel. Its internally balanced. They have done a good job for me in the past.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Instructor
Joined: Jun 2008
Posts: 203
Likes: 32
From: warrenton virginia
If you are going to replace your flywheel,why not use the flywheel from a 84-85 c4 with the 2 piece rear seal . its the same flywheel used on the 396-425 and the L-88.the engine will rev faster because it has less rotating mass.
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Light is better in my opinion
Hi, picture of my stock flywheel 66 L79 327/350 weighs in about 35 lbs.
When I rebuilt engine, Blockman suggested a lightweight flywheel at 15 lbs.
Had it balanced and matched to clutch and boy , with my 3.70 rear and wide ratio 4 speed, it makes a difference. You do have to get used to faster revs and faster loss of revs.
But I have the stock flywheel on the shelf.
Jack
When I rebuilt engine, Blockman suggested a lightweight flywheel at 15 lbs.
Had it balanced and matched to clutch and boy , with my 3.70 rear and wide ratio 4 speed, it makes a difference. You do have to get used to faster revs and faster loss of revs.
But I have the stock flywheel on the shelf.
Jack
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
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
Race Director
Joined: Feb 2007
Posts: 15,468
Likes: 8,950
From: northern california
C2 of Year Finalist (track prepared) 2019
I can't think of a reason, other than stinginess, to trust ancient metallurgy.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
im pretty sure that wheel is for an externally balanced engine bwdik?
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
Somebody please tell me how a flywheel "goes bad" just because it's old?
Worn, heat cracks, surfaced too many times, been sunk in a swamp or other abuse, yes. Age, ?????????????????????????
Worn, heat cracks, surfaced too many times, been sunk in a swamp or other abuse, yes. Age, ?????????????????????????
Safety Car
Joined: Sep 2004
Posts: 4,049
Likes: 134
From: St. Clair Shores MI
C2 of Year Finalist (track prepared) 2019
2017 C2 of the Year Finalist
Team Owner
Joined: Mar 2003
Posts: 26,118
Likes: 1,874
From: Greenville, Indiana
That's pretty dramatic. 800 hp? That would come under abuse, heat cracks or?????????
What does that have to do with age?
Race Director
Joined: Mar 2001
Posts: 14,634
Likes: 4,684
From: Mustang OK
2026 Corvette of the Year Finalist - Modified
2025 c1 of the Year - Modified Winner
2024 C1 of the Year Finalist - Modified
2023 C1 of the Year Finalist - Modified
2015 C1 of the Year Finalist
Race Director
Joined: Feb 2007
Posts: 15,468
Likes: 8,950
From: northern california
C2 of Year Finalist (track prepared) 2019
Team Owner
Joined: Nov 2005
Posts: 28,223
Likes: 2,872
From: Beach & High Desert Southern California
For the cost, I would get a new flywheel and upgrade to a steel SFI Certified flywheel.
This Flywheel Link gets you to some moderately priced SFI flywheels that are superior to the stock iron. You have a choice between 18# and 29# models for a 327'.
I understand that NCRS does not judge a flywheel, so a steel SFI flywheel is one area where a safety upgrade is not in conflict with a goal of zero judged point deductions.
This Flywheel Link gets you to some moderately priced SFI flywheels that are superior to the stock iron. You have a choice between 18# and 29# models for a 327'.
I understand that NCRS does not judge a flywheel, so a steel SFI flywheel is one area where a safety upgrade is not in conflict with a goal of zero judged point deductions.
