sbc fuel pump pushrod question

Today i discovered the threaded hole in the front of the block that goes through to the fuel pump pushrod bore, doesn't.

It's a blind hole, doesn't go through to the bore.

Did GM change this a some date?

Has anyone ever drilled and tapped the hole, or know anything about doing it?

The reason i ask was I planned on using a roller tip pushrod, and that hole is required.

Thanks

 

I can't say I ever noticed a block that wasn't drilled through and tapped except a later versioin that had no fuel pump rod hole such as some later vortec versions. Just finish drilling the hole through and tap it if you need more threads.