tapping oil out bore in block

hi, just wanna ask if anybody here has made this modification.

as i´m very limited with space due to the self made headers i´m using - can only run a relocated oil filter, and have used a 90 degree adapter with that kind of screw on relocation adapter thing, (like it is sold in these sets on eBay etc.) to get the oil hoses away from headers and block.
Drawback on that combination of things: i can not switch the complete engine. If i want to pull the motor i have to pull the heads first and vise versa when trying throw a new motor in - first block than heads...

so i want to take the chance to modify the oil in / oil out thing and get rid of all that stuff, and plumping my hoses directly into the block.

i found a short describtion what to do in the "how to hot rod mopar small block engines" book from Larry Shepard.
but i wanna ask the crowd here before going wild and ruin the block

the describtion says to block the bigger oil in hole in the middle (should be 3/4x .75") and drill and tap the small oil out hole to 3/8 NPT size

so i gonna ask.. anybody done this before ?