73 corvette flexplate question
Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
Safety Car
Joined: Sep 2012
Posts: 4,688
Likes: 41
From: Palm Harbor, Florida
well then he could grind the weight off if that were the only difference. but the center of the crankshaft is larger then on the 350, even if bolt pattern is the same, which I don't think it is. center is different
Drifting
Joined: Jan 2006
Posts: 1,832
Likes: 38
From: Cedar,BC
Up to 1986 or so the sbc and bbc crank flanges are the same,the only difference is the imbalance weight added for the 400 or 454.You could knock the weight off,but why bother SBC flexplates are dirt cheap.
Safety Car
Joined: Sep 2012
Posts: 4,688
Likes: 41
From: Palm Harbor, Florida
hmmm. I certainly could have had flexplate that was improperly labeled as "350", maybe it was for a 305 or something? but the flange was definitely smaller then the 400 crank used on my 383
Safety Car
Joined: Sep 2012
Posts: 4,688
Likes: 41
From: Palm Harbor, Florida
I just measured the size of the hole on the flexplate that I had laying around with the label "350" on it. 2.06 inches with my micrometer. pretty sure I read it correctly. what size is flange on those crankshafts?
Last edited by Doug1; Jan 14, 2013 at 08:00 AM.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
I don't know what flexplate you have, Buick, Olds?? All chevy's of that era could physically be interchanged with the only difference being the counterweight for 400's and 454's.
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
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
what's the diameter of the plate you need? 10 1/2 " or 11"? the bbc need the 11" which has 168 teeth, the sbc needs the 10 1/2 " that has 153 teeth. check the bolt pattern on the converter. the pitch is the same on both, the difference is the circumference. i just changed a sbc muncie to a th400 that was from a bbc. the 10 1/2" flex that i bought wouldn't bolt to the bbc converter. i used the original flex plate that bolted to the sbc without a problem. if you want a 10 1/2" flex plate , i've got a brand new one for sale!
Last edited by jnb5101; Jan 14, 2013 at 07:13 PM.