RarityBoiAtl,

Slow down!

You've got a horrible situation there and you are about to make it worse.

I'm not familiar with the 850 tappet design, but it may well be, as Arno stated, that your spongy tappets are the defective ones and the non-resitant tappets are good.

It all has to do with how oil pressure is maintained within the tappet. Some tappets have an internal check valve. Others, by virtue of their position in the tappet well and their alignment with a oil passage, fill and check themselves by exposing, and closing, that passage connection.

Regardless of how they work, what arno said about resurfacing them and making sure they go back in the same location, IS CORRECT. You can't just put any used tappet in any engine. You can, of course, but you're asking for problems down the road.

Have you recorded the original tappet locations?