what tranny do i have

i have a 91 dx Honda civic hb......an when i got it it had a zc block an a d15 head an i don't know what tranny i have so i dont know what axles i need

I'm 99% confident you need dx/si axles. The fact that your car is a dx means it has dx/si hubs. I dont think the previous owner would have been dumb enough to through in an STD tranny, and have to downgrade the hubs to HF/STD ones. So in this case you would have either a dx or si tranny (both use same axles).
The only other alternative would be if you have a ZC tranny. I'm not too keen on the ZC trans and dont know what axles to use with it. I've only heard horror stories about people using 1st gen teg axles with it and having them rip out.

90/91 DX/Si axles are the same. If you car is a 5 speed it must have a DX/Si tranny. Check on the tranny there should be some markings near the tranny oil fill... my Si tranny says PL3/3000 on it, my DX says PL3/4000. Good luck.
Dan

my says pl3/4000 on it but so i guess it a dx tranny but then i went to go get a clutch kit for my car it didn't fit my old clutch that was on there had 21 splines an a dx haves 20 splines