I recently rebuilt a B20 just with new rings, rod & main bearings and a B20 E head modified for the IPD double valve springs and also using the IPD lifters and pushrods.
I did not 'take out' the IPD street performance cam because it only had 38K on it with new cam bearings installed at the machine shop in 1996. I left it in the block with the fiber timing gear attached while I installed the new main & rod bearings.

Since my recent rebuilding , of course there is a need to adjust the valves after 50 miles or so and there was plenty of oil under that valve cover.
I know this because I adjusted the valves again at 200 miles or so and the top of the head was well oiled.
Now there is about 350 miles on the new rebuild and there isn't any oil getting up through the whole in the engine block!!! Bone dry! Broke 2 heads off the IPD pushrods.
The B20E head is sitting on the work bench now and that oil hole on the #3 rocker arm stand hole is perfectly 'clear' with no restrictions. I even checked this twice on intial rebuild.

WHY ISN'T AIR OR OIL COMING THROUGH THE CANAL THROUGH THE ENGINE BLOCK WHEN I BLOW 120# COMPRESSED AIR THROUGH IT WITH OIL FILTER OFF?
I CAN'T BELIEVE THAT THE CAM BEARING 'SLIPPED' SO THAT THE HOLE ISNT LINED UP ANYMORE.
HAS ANYONE HEARD OF THIS? I really don't want to yank out the engine again.
Any help appreciated. Duck