I have a f22b2 block and a h22a4 head I know when you put it together it has low compression but what kind of pistons can I use to bump up the compression

 

Any F22B2 85mm aftermarket piston that has a higher dome volume will raise the compression accordingly. Wiseco, Arias and CP all make them.

Taking into consideration that you are building an OEM hybrid. I suppose you are looking for an OEM cast piston that you can throw in there for cheap. Try an 86mm bore and use a K20a1 piston. They have am 86mm diameter and 4.25cc dome with a compression height of 30mm.

That should effectively raise your compression to 10.8:1. 11:1 if you do some minor head & block milling.

Now in saying that you won't be able to use floating wrist pin pistons (H22/H23/K20/K24) without modifying your F22 rods.

 

So to use the k20 pistons the block just needs to bored out to 86 mm?

 

Yes, it will need to be bored and honed. Remember that you'll need to modify the rods to accept the different style of wrist pins.
Boring out the engine will take it from 2156cc's and bring it to 2207cc's. If you bore it to 87mm it can accept H22/23 & K24 pistons which will raise it to 2259cc's (2.3L).

I do not know the specifics in their dome displacements and comp heights but I'll try and remember to look into it if someone doesn't chime in with the numbers soon.

 

K how do I make the modifications to the rods

 

You have to take them to a machine shop and have the piston end honed (enlarged) and fitted with a bronze bushing.