people can debate on why this is a waste of money and why its a great investment. one thing people seem to get confused on is why they would need it in the first place.
on a stock motor with mild cams and VT you will probably not benefit from this mod as people have proven with high mileage mild cammed cars. i took apart my friends built K24 with roughly 40k on the motor after it had a piston skirt break off and I noticed this on his 5th cam tower
the car had a supertech VT with DC4 billet cams. the intake cam was slightly scraped up so i was able to polish it off and save the cam but the tower is trash.
now don't think you can just run over to honda and buy a new tower, you will have to buy the entire cylinder head to get them. lucky for my friend i have extra sets of towers on hand. we decided to make the investment and have the tower modified by john @ hytech exhaust.
you can see how a groove is milled into the tower and drilled to have oil pumped through the -4 an fitting
lastly as part of the modification your rocker shafts must be plugged to prevent vtec rocker to be engaged at all times.
Hytech will supply you with a T union to use your OEM oil pressure sender and attach the oil feed line to the 5th tower. i decided to ditch the T and drill and tap the block instead. i did not want to re tap the sender hole to a 1/8 NPT
hopefully this clears up peoples questions and confusions on the mod.