Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

Head casting number

Thread Tools
 
Search this Thread
 
Old 02-09-2009, 09:27 AM
  #1  
Senior Member

Thread Starter
 
chas0218's Avatar
 
Join Date: Jun 2008
Location: Corning NY
Posts: 660
Likes: 0
Received 1 Like on 1 Post
Car: 86' IROC
Engine: 388
Transmission: Built 700r4
Axle/Gears: 3.08 non-posi
Head casting number

My head's casting number is 3947041, here is the info i got on the head 3947041....69-70...302/350......"Right angle" casting identifier, 64cc chamber, accessory holes, good HP head

my question is what is the size of the intake runners?...would it be the same as the 3947041X head (165cc intake runner)?...also i have google the casting number several times and i keep getting 64cc and 76cc combustion chamber sizes and im not sure which is right.
Old 02-10-2009, 07:51 PM
  #2  
Senior Member

Thread Starter
 
chas0218's Avatar
 
Join Date: Jun 2008
Location: Corning NY
Posts: 660
Likes: 0
Received 1 Like on 1 Post
Car: 86' IROC
Engine: 388
Transmission: Built 700r4
Axle/Gears: 3.08 non-posi
Re: Head casting number

anyone?
Old 02-10-2009, 10:31 PM
  #3  
Supreme Member

iTrader: (3)
 
jamon8's Avatar
 
Join Date: May 2005
Location: Southern IL
Posts: 1,942
Likes: 0
Received 0 Likes on 0 Posts
Car: 88 GTA "Cocaine"
Engine: 350 tpi
Transmission: 700r4
Axle/Gears: 3.27
Re: Head casting number

what did they come off of

most of the guys who are know this kind of stuff are not always looking to talk about that old of stuff on these boards

maybe a corvette site

I dont know
Old 02-10-2009, 10:49 PM
  #4  
TGO Supporter

 
Stekman's Avatar
 
Join Date: Jul 2003
Location: Grand Rapids, MI
Posts: 4,803
Likes: 0
Received 0 Likes on 0 Posts
Car: Z28
Engine: Sb2.2 406
Transmission: Jerico 4 speed
Axle/Gears: Ford 9" 3.60
Re: Head casting number

They're pretty much identical to the 186 castings. Couple different intake valve sizes, either 1.94 or 2.02. 64cc chambers and 160cc intake ports. The "x" versions are same except +5cc's on the ports, if memory serves me correct.
Old 02-10-2009, 10:52 PM
  #5  
Member
 
iroc.86's Avatar
 
Join Date: Jan 2008
Location: Austin, Texas
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
Car: 86 iroc
Engine: 383HSR
Transmission: custom 700r
Axle/Gears: moser 9" 3.90
Re: Head casting number

the runner vol btween the two heads is more than likely the same ,163cc as the factory heads almost all have pretty small runners!

as far as the combustion chamber vol. could be either only way to know would be to measure yourself. hope this helped

that is a great casting though with some clean up! i have a pair myself
Old 02-11-2009, 08:10 AM
  #6  
Senior Member

Thread Starter
 
chas0218's Avatar
 
Join Date: Jun 2008
Location: Corning NY
Posts: 660
Likes: 0
Received 1 Like on 1 Post
Car: 86' IROC
Engine: 388
Transmission: Built 700r4
Axle/Gears: 3.08 non-posi
Re: Head casting number

I plan on porting and polishing them hopefully get some more flow out of them...im building a 383 so do u think these heads will flow enough after the port and polish?
Old 02-11-2009, 08:59 AM
  #7  
Supreme Member

iTrader: (3)
 
jamon8's Avatar
 
Join Date: May 2005
Location: Southern IL
Posts: 1,942
Likes: 0
Received 0 Likes on 0 Posts
Car: 88 GTA "Cocaine"
Engine: 350 tpi
Transmission: 700r4
Axle/Gears: 3.27
Re: Head casting number

man these guys know their shizzel

I dont know if I will ever get that technical with stuff

the guys on thirdgen.org

ROCK
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
1992 Trans Am
History / Originality
27
05-10-2023 07:19 PM
evilstuie
Exhaust
24
02-28-2016 03:33 PM
camaro71633
Tech / General Engine
39
09-01-2015 10:24 AM
BlackphantomZ28
Engine/Drivetrain/Suspension Parts for Sale
0
08-22-2015 01:00 PM
dcbsracing007
Cooling
0
08-18-2015 07:24 AM



Quick Reply: Head casting number



All times are GMT -5. The time now is 11:14 AM.