Hello.

does anyone have experience with the coolant hose fitting and thread pitch? I would like to plug this for a cleaner look.

 

Hi, these are the part numbers for the OEM plug and washer : 12208-PR3-000 Bolt, Sealing (20mm)
12209-PR3-000 Washer, Sealing (20mm).

 

Measure them to be sure.

I prefer to use calipers to measure metric threads. here are some cheap ones if you want a set for yourself. tape measure or ruler with a metric scale work too for most cases.

looks like M20X1.0 to my eyes.

 

Measuring isn't necessary in this case... the part numbers provided just above your post are for the end plug/sealing bolt caps for the VTEC rocker arm oil rail bars found on the "B" and "H" series engines. They DO in fact, fit the hole for the original heater hose outlet barb.

EXCELLENT first post !!! Short and sweet... very informative... and absolutely correct. It is quite refreshing to see a new members' first post actually assisting others instead of begging for immediate help with their emergency issue and then bumping the thread one hour later if they don't have any answers !!!

Welcome to the board.