799 heads, milling question
Thread Starter
Teching In
Joined: Dec 2013
Posts: 11
Likes: 0
From: North Carolina
799 heads, milling question Hello,
I have a 2004 GTO with the LS1 in it. I have found a guy about an hour away from me that has a set of 799 heads available with brand new Z06 valve springs installed. He knows they have been milled (prob someone had them on a 5.3 previously) but he's not sure how much. He is going to have the chambers measured before I decide to purchase them.
My question is what is the maximum they can be milled to fit my LS1 with no valve clearance issues etc. I'm actually pretty happy they are milled cause I'll get a bump in compression, but I don't know the formulas to figure out what my compression will be and if the valves will have clearance and also if the stock push rods will work. I'm ok with buying new pushrods if needed. But could someone let me know what the max MM the head could be milled and still work on my LS1?
What would be awesome is if someone had a list of what the compression would be and what size push rod if need for each mm taken off. I believe stock untouched they are 64mm correct?
Also will I still see a good gain slapping these on if my only mods are a CAI and cat back exhaust? The 04 GTO's came stock with the LS6 intake and TB on it. But I don't have longtubes yet. I should still get a pretty decent power increase right? He's selling them dirt cheap so I can't pass this up as long as they are not milled to much.
Sorry for the huge post. I'm new and very enthusiastic!!!
I have a 2004 GTO with the LS1 in it. I have found a guy about an hour away from me that has a set of 799 heads available with brand new Z06 valve springs installed. He knows they have been milled (prob someone had them on a 5.3 previously) but he's not sure how much. He is going to have the chambers measured before I decide to purchase them.
My question is what is the maximum they can be milled to fit my LS1 with no valve clearance issues etc. I'm actually pretty happy they are milled cause I'll get a bump in compression, but I don't know the formulas to figure out what my compression will be and if the valves will have clearance and also if the stock push rods will work. I'm ok with buying new pushrods if needed. But could someone let me know what the max MM the head could be milled and still work on my LS1?
What would be awesome is if someone had a list of what the compression would be and what size push rod if need for each mm taken off. I believe stock untouched they are 64mm correct?
Also will I still see a good gain slapping these on if my only mods are a CAI and cat back exhaust? The 04 GTO's came stock with the LS6 intake and TB on it. But I don't have longtubes yet. I should still get a pretty decent power increase right? He's selling them dirt cheap so I can't pass this up as long as they are not milled to much.
Sorry for the huge post. I'm new and very enthusiastic!!!
