i picked up a 91 ef 4spd hatch and bought a hf/si cluster ...put it in and its off by about 15mph under.....
i have my oprg cluster can i just replace the speedo portion with my old one
or should i get a 5spd vss on the tranny side?

 

I swapped the speedo gauge from my std to si cluster just to keep my og miles. It will work just fine.

 

do i just take the cluster apart?

 

yay i found a vid on youtube ....took 10min and worked like a charm