I'm rebuilding an 97Lt1 and I was wondering if I could plug these holes up in the back of the cylinder heads or do I have to put the Water transferring tube that connects both cylinder heads with the line that comes off the radiator along the intake. Any help would be greatly appreciated.
Thanks 1SICSS,

 

You have to use the steam vent tube or you'll run a risk of having steam pockets in your cylinder heads.

 

ditto. Keep the pipe!!!!

matt