does anyone know what tachometer if any fits in rightside clock pod of 70 ss chevelle dashpad

Not sure what you mean.

70 SS dash pad has 3 seperate holes in dash ,left one is gas guage ,middle is speedo, right is blank face . allthree have clear plastic lenses. my question is does anyone make a tachometer that size,a brand and or model that would fit in the blank right side,hole next to the speedo.thanks.

You could put a factory tach in that empty space and just wire it separately. Check out this site that "David in GA" just introduced me to. Sounds like he offers factory tachs. You must be aware that your instrumentation would not be correctly set-up though. in order to have the original appearing set up, you would need to purchase an entire guages cluster (one without the warning lights and without the large gas guage).
http://www.tachman.com/

idoit light gauges had gas, speedo,clock/blank. Tach cars had tach,speedo,clock/blank, fuel gauge was small I believe. Anyway you could put a tach in the hole just have to monkey with the harnessess.

jody
71ss454
ACES