Changed out the speedo on my 93 civic dx with an si type. Now it seems to read 10-15mph high. Has anyone seen this or knows how to fix it?

 

what is an si type?

 

civic si

 

my buddys did the same after the riceboy spec indeglow gauge face swap...after removing the needle just put it in a little lower then where it was...it seemed to work well

calculate the gears and speeds (it will not be exact since there is more to it)
http://www.sgmotorsports.com/mph.htm#GearSpeed

 

the needles work by magnestism on the back... if it's too high, push it in some. too low, vice versa