I recently bought new rocker shafts and the oil holes are smaller. The placement is the same but the new one has smaller hole. Old holes are 1/4 inch and the new ones are 1/8 inch is this a problem. The rockers seem to be getting oil. Any help on this matter would be great. Thanks
Top End Oiling Are these old stock GM shafts or aftermarket ? . GM / Chevy had much trouble over the years with too much oil getting into the rockers and then being flung about & sucked down past the valve guides & causing the occasional puffs of blue smoke . The flip side was , insufficient oil reaching the rockers and causing severe wear on the rockers & shaft , this caused complaints of tappet noise from loose & wobbly rockers . So , they constantly changed various parts of the oiling system trying to get the *perfect* balance between volume and proper lubrication . As long as you see oil coming out the weep holes on the tops of the rockers when the engine is off idle , you're fine , no worries . One more reason why you want to run thin , fully synthetic oils in your engine as soon as it's fully broken in . Remember : quiet valves are always a BAD THING in Old Tech engines ! . I hope this is helpful .
Thanks again Nate The new shafts are aftermarket not NOS but do seem to be getting oil out the rocker vent. Thanks again for the info.
No Worries ! You're welcome . These old Tech engines are really well designed to give long life service in terrible conditions , even when totally worn out ~ so just take good care to do the best works you can on it and it'll run fine for longer than you'll live .
Lubrication You don't want high pressure , you want high volume . As long as oil comes out the rocker weep holes above idle , you're good to go .