I searched through dozens of threads last night, but couldn't find an answer. The only info I could come up with is about the B18C5 ITR pulley vs. a regular B18. My car is a 99 Civic Si, but a shop installed a B18C1 shortblock 10 years ago, and I have no idea if they kept the pulleys that may have been on the block, or used the existing stock pulleys from my B16A. I just want everything to work as it should, and I'm not at all interested in an underdrive pulley. The reason I ask is because the GSR pulley is about $60 more than the EM1. Does anyone know what the differences are?

 

https://honda-tech.com/forums/acura-...ulley-2485359/

The second post says that the B16 crank pulley is smaller than the GSR's - which is true. On my engine, I have a B16 crank pulley and when I tried using an Integra alternator belt, it was too long and couldn't tension properly.

 

I'll order the GSR pulley, thank you!