Grooving lifter bores

Rusty,

There is no problem grooving the lifter bores, you just want to groove the bore on the correct side to oil the cam lobe before it rides under the lifter. If there is an oil pressure difference, I doubt you'd see it, maybe a couple of pounds at most. In my GMC truck, I built the motor years ago, and it runs great. Ask Leeana, she's been in it a few times. The groove amounts to a little more than a deep scratch, and it goes from the main lifter oil galley to the bottom of the lifter bore. Actually, it goes from the bottom of the bore up to the lifter oil galley (using the tool, you pull "up"). Same difference.

Russ.