aobrien14

So, preemptively had the potential exhaust valve issue taken care of. Heads were reinstalled, but mechanic called to say water was puking out the back of both heads :-(. I've now got two part numbers for potential plugs (12602540 and 12602048), but am doubting either can be installed with the heads in place...

Wndotintman

You can install the bolt on plugs without removing the heads. The intake will have to come back off though. No biggie.

Mark2009

Now you need to be concerned that the front crossover pipe is working (the holes are not plugged... probably are since he apparently installed the heads backwards).

You'll need to pull that little crossover pipe and check while you've got it apart. I think you can drill the plugs out in place but am not 100% on that.

Blackonblacksls

Yeah I has a set or ls7 heads that didn't have bolt in plugs.

But a set tapped into place.

I had to drill then out to vent all 4 corners.

Make sure that those aren't in place in the front like said above

aobrien14

Thanks, guys.

c5racr1

Had the same thing happen. I just installed the tube on the rear and ran a hose to the front. Works fine. Besides the rear cylinders tend to run a lil hotter than the front. Been running it that way for about 6 months. Much easier than drilling and tap.

Dirty Howie

Had this exact problem when my heads were done. Intake needed to come off and back on but they were able to install the proper plug.


DH

Z06 Steve

does 2008 and newer have 4 plugs and no cross over in the front?

LT5 John

When I did my heads on my 2008, the rear of the heads had plugs, the front had a crossover...

Z06 Steve

ok on 2008+ they went from bolt down plugs to rivit plugs

ATC399

So nothing was wrong with your Z until had it "fixed"...ok

LT5 John

In addition, my 08 Z was an early build date...

nitrojunky

re: the crossover pipe vs plugs, good point; however, on mine, the plugs are removable, nothing required to drill out. i think they use the same bolts as the crossover pipe; block with plug was the same size and interface shape as the block with attachment for the crossover pipe. (editL mine is a 2006)

Blackonblacksls

Seen them like that on everything except for 1 pair of ls7 heads.