yes this is a real question
#1
TECH Resident
Thread Starter
iTrader: (19)
Join Date: Jun 2005
Location: Los Angeles, CA (Burbank)
Posts: 755
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
How does an engine shop/machine shop know what specs a pair of heads should have when rebuilding them?
I get that an LS engine shop will be familiar with LS heads, but what if I needed gen I sbc heads rebuilt or late 60s-early 70s pontiac heads rebuilt? i know they rebuild heads from all kinds of performance applications but how do they know how much spring tension each head should have, or what diameter the valve stems need to be? Do they cross reference a database or look this up in a factory book?![Icon Confused](https://ls1tech.com/forums/images/smilies2/icon_confused.gif)
i'm embarassed i don't know this but am dying to know
thanks again guys
I get that an LS engine shop will be familiar with LS heads, but what if I needed gen I sbc heads rebuilt or late 60s-early 70s pontiac heads rebuilt? i know they rebuild heads from all kinds of performance applications but how do they know how much spring tension each head should have, or what diameter the valve stems need to be? Do they cross reference a database or look this up in a factory book?
![Icon Confused](https://ls1tech.com/forums/images/smilies2/icon_confused.gif)
i'm embarassed i don't know this but am dying to know
thanks again guys
#4
TECH Enthusiast
iTrader: (118)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Depends on the quality of the shop.
Id say most places would have a good idea... but just because they machine heads doesnt mean they know anything about the heads they are machining, or what you want out of the project for that matter. Machining a stock ls1 head someone could be doing a stock cam... someone else could be doing a .650 lift and needs dual springs... same head, same car, different application, different springs.
You should do the research and get the spings you want. IMHO
Id say most places would have a good idea... but just because they machine heads doesnt mean they know anything about the heads they are machining, or what you want out of the project for that matter. Machining a stock ls1 head someone could be doing a stock cam... someone else could be doing a .650 lift and needs dual springs... same head, same car, different application, different springs.
You should do the research and get the spings you want. IMHO