Banana grooves..

The grooves I've had on mine were not parallel with the shaft. Almost if you could take the edge of a triangle file and put it at a 20° angle to the shaft right over the hole and file until you get a certain width that is already pretty much scorn into these older shafts anyways...
I was thinking putting the shaft in my vise in a soft cloth of course with the holes facing up and again going at somewhat of a less than 45° angle right across the center of the oiling hole and filing until I get the correct width which would probably be pretty close to the correct depth...
The heads that I have which are left overhead from the duster before I put on the speedmasters or 596 heads rebuilt with new k line guides hardened seats and 202 valves... I think the Crower Springs were 135 to 340 ? Spring pressure... I originally had 273 rockers on them (banana grooved) before I bought the Hughes roller rockers.. I stupidly sold them after they were machined for spring clearance and I filed the tops of the adjusters for comp locking adjusters...
I have to give everything on this a severe cleaning and pull out one of my heads to get them all clearanced correctly over the springs... I remember the machine shop at the back cut them..