383 Stroker?
Thread Starter
Instructor
Joined: Feb 2021
Posts: 144
Likes: 17
383 Stroker?
So when I bought my Vette I was told it has a built 383 Stroker motor making 505 to the crank. But recently I have come to doubt that. I took it to the drag strip and was only running 14.6s however my carburetor was messed up. Since then I have fixed it however I have not been back to the strip to see. So my question is how can I tell if it’s actually a 383 Stroker?
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
So when I bought my Vette I was told it has a built 383 Stroker motor making 505 to the crank. But recently I have come to doubt that. I took it to the drag strip and was only running 14.6s however my carburetor was messed up. Since then I have fixed it however I have not been back to the strip to see. So my question is how can I tell if it’s actually a 383 Stroker?
Race Director
Joined: Mar 2017
Posts: 11,949
Likes: 4,507
From: Virginia
Perhaps start by taking some photos? One of the smarter members might be able to tell with a borescope, either by looking at the crank through the oil drain hole, or measuring the stroke through a spark plug hole.
But please start with the engine stamp pad.
But please start with the engine stamp pad.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
and the harmonic balancer and see if you can see the starter wheel or flywheel through the starter hole. if is is externally balanced, and most are, you will see counterweights on the balancer and flywheel. you might be able to get piston at tdc, put a piece of coat hanger on top of piston, mark the hanger at the edge of the plug hole and crank the engine slowly so the piston and hanger go to BDC then mark the hanger again. may be able to tell 3.48 from 3.75 inch of travel.
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
So when I bought my Vette I was told it has a built 383 Stroker motor making 505 to the crank. But recently I have come to doubt that. I took it to the drag strip and was only running 14.6s however my carburetor was messed up. Since then I have fixed it however I have not been back to the strip to see. So my question is how can I tell if it’s actually a 383 Stroker?
i had afr gauges to tune the carb and a MSD controller for programable timing
any stamp. / number on the engine
my zz383 had a GM serial tag
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
So when I bought my Vette I was told it has a built 383 Stroker motor making 505 to the crank. But recently I have come to doubt that. I took it to the drag strip and was only running 14.6s however my carburetor was messed up. Since then I have fixed it however I have not been back to the strip to see. So my question is how can I tell if it’s actually a 383 Stroker?
One quick way if it's a cheaper externality balanced. The damper is drilled for external balancing
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
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Well....if it is making 500hp.....it has a fairly hot cam and a very good flowing set of heads......also at least an Air-Gap style intake.....What size carb?
If it has premium components on it like that then most likely it is a 383..........also, look at the balancer for a notch cut out of the outer shell, holes drilled as previously stated, and/or a weight bolted on the hub.
Don't get too crazy about it......the only difference between a 355 and a 383 is .270 inch of stroke.....focus on getting it running properly. A warm 350 will run 14.60's......something is off.
Jebby
If it has premium components on it like that then most likely it is a 383..........also, look at the balancer for a notch cut out of the outer shell, holes drilled as previously stated, and/or a weight bolted on the hub.
Don't get too crazy about it......the only difference between a 355 and a 383 is .270 inch of stroke.....focus on getting it running properly. A warm 350 will run 14.60's......something is off.
Jebby
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
A 383ci making 500HP would be a little radical. If it idles smooth then you are not making that HP. As others have said it is an externally balanced engine and you should be able to look at balancer and figure it out. I know everything is 800+HP these days but it it is still hard to hit 500HP N/A with a 383ci and have a nice driver.
Race Director
Joined: Jul 2018
Posts: 10,591
Likes: 8,415
From: San Antonio, TX/Mahopac, NY
2026 Restomod of the Year Winner
2024 Corvette of the Year Finalist - Modified
2024 Corvette of the Year Finalist - Unmodified
2023 C7 of the Year Winner - Modified
Put a vacuum garage on it and share how much vacuum it pulls at idle, then share a bunch of pictures of the engine, intake, heads, balancer, etc. we can give you a pretty good idea.
Melting Slicks
Joined: Sep 2010
Posts: 3,306
Likes: 697
You can buy internally and externally balanced 383 kits. If it really made 505 hp at the crank it would need quite a large cam. I don't think a 670 cfm will get you 505 hp. I would ask for the dyno sheets if the previous owner did have it on an engine dyno. I would ask for the engine build sheet with cam specs.
Got to start with the basics. Check the timing curve. Check base timing and at full advance. Check fuel pressure. Do a compression check. Make sure you are getting fully opening carb blades at full throttle. Make sure your ignition system is up to snuff. Check spark pugs.
Got to start with the basics. Check the timing curve. Check base timing and at full advance. Check fuel pressure. Do a compression check. Make sure you are getting fully opening carb blades at full throttle. Make sure your ignition system is up to snuff. Check spark pugs.
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
Wait this is the car with the blue flex fan with no clutch and improperly wired electric fan in front of it and no shroud right?... I'm going to say the previous owner just wanted to believe it had 505hp and its not been tested...
as far as the 670 size having any real noticable effect on hp numbers... when you use any type of dyno software there is maybe 12hp difference at WOT between a 670 and a 750.. Its just not going to be the game changing factor here unless your looking for that 12hp
as far as the 670 size having any real noticable effect on hp numbers... when you use any type of dyno software there is maybe 12hp difference at WOT between a 670 and a 750.. Its just not going to be the game changing factor here unless your looking for that 12hp
Last edited by augiedoggy; Jun 28, 2021 at 10:34 PM.
Thread Starter
Instructor
Joined: Feb 2021
Posts: 144
Likes: 17
Yep sure is. That’s why I’m trying to get to the bottom of it to know how I need to go about working on it
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
I do see a block off plate where the fuel pump would be so theres got to be an electric fuel pump.
Last edited by augiedoggy; Jun 28, 2021 at 10:44 PM.
Thread Starter
Instructor
Joined: Feb 2021
Posts: 144
Likes: 17
All I really know about the intake is it says Edelbrock and Performer. Haven’t really gone that in depth with taking stuff apart for fear of some of that bubba work not working anymore afterwords.