Is there ANYTHING I can do to a 3rd gen with a poser b series? I can't find for the engine internals. If there isn't anything I'll get rid of it

 

You dont want to spend money on a B21a1, it was the first FRM sleeved block, and unfortunately most of us 3rd genners just chuck it or keep it running until we swap out for the H22/23, F22B, F23, F20b series motors.

The civic/integra B series motors obviously do not drop in. There are a few B series swappers but the mounts are not massed produced plus you need to extend the length of the Rod shifter to make it work as well.

If your B21a1 is not burning oil, just get a intake, header, and catback. Or if you are so inclined too, get a B20a5 or B20a Block and then you can either overbor to match the B21a1 bore and specs, then boost that motor for some real fun 200+ power.

 

Thing is I have no idea where to get engines or how to swap!

 

Our preludes b series were the First....all other b series blocks were stemmed from that designed.

^...Really? Then why are you contemplating internals? There is some aftermarket, bolt ons, and options for more power, but it's whether you are up to the challenge. If you what and easy car to build then this is not for you.