Valve replacement

I have 2 engines a 1987 2L and a 1990 2.2L. The 87 2L is in my 90 B2200. Does the head have to be removed to replace the valve guides and seals, or are the heads interchangeable?

I have 2 engines a 1987 2L and a 1990 2.2L. The 87 2L is in my 90 B2200. Does the head have to be removed to replace the valve guides and seals, or are the heads interchangeable?
They are interchangeable. The 2.0 head has adjustable rockers and the 2.2 has hydraulic lifters. Basically the same. As 4 the guides & seals I'm sure u have to take the head off even though I've never done it.

I dont believe you need remove the head to replace guide and seals. Use compressed air so valve doesn't drop in. I have not done the procedure on a mazda however. Perhaps someone will chime in with more skills than me.

Yes the heads are interchangeable.
Which one needs a valve guide and seal job?

If you are just changing the valve seals, you do not have to remove the head from the block. But you have to remove the rockers to get to the seals. To remove the rockers, you have to pull out the timing belt and the camshaft pulley. Then you can pull out the intake and exhaust valve seals one at a time using a valve compressor to remove the valve springs and keepers. To keep the valve from dropping inside the combustion chamber, you have to apply compressed air through the spark plug hole to keep the cylinder pressurized. Since the rockers are already out, you can clean the hydraulic lash adjusters on the 90 2.2L before you put it back to make sure they will keep the oil and stay pressurized for quiet valve operation.

Are you swapping engines or just the heads?

Oh, if you are changing the valve guides, the head needs to come off the block and sent to a machine shop.