Set the valves to zero lash and still had the knocking. Put the stock valve train back on and and the knocking is gone. I did have a tapping sound in the motor, for about 20 seconds, when I shut it off though. I think it was a lifter bleeding down. I'll just keep the stock train in until I can clearance the heads or maybe try some 1.5 rollers which would push the rods out a little but I'll still probably need to clearance the heads. Thanks for all the responses. Appreciated.
I have a few ideas.. On trying to compress a lifter when full of oil... Trying to do this by hand will not work. If you use a vise with jaw protectors or a C clamp, you will note oil coming out of the hole and it will compress slowly. Thye are not simply a oil supported plunger. They are engineered to not bleed down really easily. Anti pump up, or variable duration lifters take that to another level. Those two thend to be a little more noisey. Noise in hydraulics can be for different reasons. You say you set the lash to 0. The deal with hydraulics is they need preload, not "lash". Lash is air spaec in the valve train. Preload is the amount of travel in the plunger of the lifter you create by the rocker adjustments. I didn't read where you experimented iwht more of less preload... But the spec I use is .030" to figure pushrod length, and for most rockers, that's somewhere around 1/2 to 3/4s of a turn past "0" preload. Also, if you use 3/8 pushrods then they also offer less pushrod clearance in the stock holes. Add the pushrod cup position as you noted of the 1.7s, and they may be hitting the heads at full lift or close. The 1.5 rockers are all the same pushrod postition. So if the stock hydraulic stuff is quiet, the roller types of the same ratio will work fine too.
