Yelo

I just realized this after reading the post about p/v clearances....when I did the head swap I wasn't thinking much about it at the time due to the 1500 other things I was thinking about but I KNOW they were flat (I had to clean coolant and junk out of 8 cylinders...I ought to remember)

I was under the impression that the LQ4 had dished pistons and the LQ9 had flat-tops, with the flat-tops and 66.67cc chambers my compression is gonna be ALOT higher than the 10.1:1 that I figured on....closer to 10.8:1

is it possible that the 99-00 6.0's with the Iron heads had flat-tops ???.....I'm pretty sure just by eyeballing it that the Iron head chamber is bigger than 71cc, is it possible that GM went with flat-tops to bring the compression in line due to larger chambers ??

BigTex

iTrader: (16)

Gonzo had a 99-00 6L. Lets see what he says.

I guess you could have a 4.8 with iron heads.

Yelo

I bought Gonzo's iron heads from him.....I went out and compared them last night to the ones I took off and they are definitely the same head

Yelo

before this turns ugly....HOW MUCH of a dish should they have ???....if it's nothing more than a concave surface across the whole piston it COULD look and feel flat, but if they are like ALL other dished pistons and it has a rim around the outside and a VERY pronounced dish then I DEFINITELY don't have dished pistons !!

gonzo 6.2

iTrader: (8)

I believe the 6.0s all have the same head chamber configuration also.Its been several years since mine was down,dont remember mine being any different than my buddys 02 LQ4,If i was to guess,I think there was a rim about 1/4 around,slight dish with valve reliefs.

Have Greggo post a pic.

JERRY2500

My pistons are flat.

Yelo

OK....now there's two of us......I feel a little better

Gonzo...that piston configuration you described is what I WAS expecting to see (same design as EVERY other dished piston), but mine are TOTALLY FLAT

JERRY2500

Same hear

gonzo 6.2

iTrader: (8)

Mine very well could be and problably is,i just cant remember.I am still under the impression all Lq4 pistons are the same.

JERRY2500

I had my heads off a couple of weeks ago, definatly flat.