i swapped my 85 mph no tach gauge cluster for a 115 w/ a tach and acc gauges, plugged it in today and all the gauges work fine, cept the tach is off, i assume because i have a v6 and it was from a v8, no trouble thou as i am swapping soon. but my question is, will my speedo be off because it just replaced an 85, or does the electronics in that compinsate for that no matter what, and if it is off how do i adjust it?