Thread: 48's
View Single Post
  #3  
Old 04-18-2012, 01:54 PM
Steve Barcak's Avatar
Steve Barcak Steve Barcak is offline
Ultimate Warrior
 
Join Date: Nov 2002
Location: Pontiac Heaven in the Arizona desert & above the White mountains in the cool country of eastern Az
Posts: 4,642
Default

Quote:
Originally Posted by U47 View Post
1969 Pontiac has three engines, 350, 400, 428. that use the # 48 big valve head. Since all the engines use flat tops with valve relief's, this means the chamber volume has to be different. Is there any way to tell them apart besides cc ing the head?

D.
I will agree that I have never heard of #48s installed on a 428. What is your info source who told you that?

Further, what you state does not mean that #48 heads had to have a different chamber size. That would only apply if they had the same compression. The 350 ended up with less compression using the same head as the 400.

Also, if you have never seen a 428 piston, they are dished, not a flat top.

__________________
Hundreds of Pontiacs in Az
"Real Pontiacs only..no corporate nonsense!"
Facebook- Pontiac Heaven
Hosting-
23rd annual Pontiac Heaven weekend- Phoenix pending due to covid
Pontiac Heaven Museum in process
Phil 2:11