Valve train tap on a rebuilt engine ............... replaced the new lifters with another set still there !!!!!!!! Adjusted the lash ........ still there ! Checked pushrods .......... still there ! causes ? (Can be heard at 2.30 onwards )

Hey Rodders, The 76 Plymouth 318 in my F100 has all of a sudden started making a tapping sound that gets faster as I rev up. I'm assuming it's a lifter or rod that needs attention, but whilst I try to find time to investigate, will it hurt to drive it about for the time being. Thanks.

Hey Guys, I need to tap a hole to fit a 1/2" x 18 bolt, but nowhere seems to sell taps this size. Have I got a really odd size bolt or am I not looking in the right places for a tap? Ta, Ady