[Jay S]

That cam card shows that it is ground on a small block “S” journal. The base circle is smaller than a typical Pontiac “B” journal. The “B “ journal will expose the top oil hole on a lot of blocks no matter what lift the cam has. To make the 2148 lifters work the cam should be ground on a small block journal, and have a max lift of .36” ish or less. A lot of people on here have “B” journal cams.

[Stan65]

It can’t slip out because the limited clearances doesn’t allow the bolt to move more than a couple degrees when the bone is held in place by the lifters.

As far as clearance, The lobe can’t be taller than the cam journal. Most lobes are roughly .010” shorter than the journal. I never measured, but there is plenty of clearance. I can put my 3/8” closed end wrench on the bolt head with the lobe directly under it at full lift.

I can measure and get a picture tonight if necessary.

Here is a pic of an early mockup with just junk bolt, washer, spring etc. you can kinda compare to the love next to it.