yes i just put a 95 b18b in my 90 a few weeks ago. runs great, cams are great, noticeable power gain. torque increase used to start at around 3500rpm, now at 2000rpm all the way to redline (w/ intake/exhaust/cat).
labor- 300-500. 120-180 for all the gaskets. get the head gasket kit (oem or aftermarket, i got the latter cuz i was cheap).
if you do it yourself, the obstacles are the crank pulley bolt and valve seal replacement tools (if you choose to replace them). also be careful with the bottom part of the pcv valve, its hard plastic and is very brittle. be gentle when removing/installing the manifold to avoid breakage. i broke mine and made an extension instead. a few of my hoses also busted so i had to replace them. i guess they wouldve been ok, but when moving stuff around like that after 12 years they just couldnt take it.
cylinder head is a direct replacement. at the least, you need to replace the head, intake, and exhaust manifold gaskets. good luck, it was my first time ever at engine internals and although it was hell for 22 days (mostly waiting for tools), it was well worth it =D
btw, the valve seals are different so you should get a 94-95 gasket kit. local shop just gave me a g2 kit and swapped out the seals. mentioned something about 96+ being different so if you have one check on fitments. i used red rtv silicone for the intake/exhaust. my intake was made of paper, exhaust and head were 3 layers of metal.
i also noticed that the 94-95 exhaust seals look identical to the intake seals (aftermarket brand mind you). i bring this up cuz in the helms it reminds you to use the white topped seals for the intake and black topped seals for the exhaust, mine were all white. this leads me to believe the valve stems are different diameters so those of you who only want to swap valves should take note.