Did the 1969 Olds 400G motors suffer from poor oil flow? I've read where the oil passages should be opened up some by drilling them out making for better oil flow. I figured while the motor is apart, that should be done. Thoughts?

 

The "G" block has the same oil passages as its brother, the 455 block. A street or street/strip performance motor will not need to have the oil passages enlarged. Restricted pushrods can be used if you will have full rollerized rocker arms. This may keep a slight amount more oil being delivered to the main bearings. When rebuilding the motor, I would recommend a high volume oil pump with appropriate pick-up and a larger sump oil pan with a good baffle. Main and rod bearing clearances on the "loose" side and adequate rod side clearance to allow the oil to flow.

 

what about cross drilling and chamfering the crankshaft, thats an old Mondello trick

 

Don’t cross drill it. All the crank manufacturers quit doing that years ago.

 

Interesting, thanks

 

good advice.