across the housing is what I gave.

hi
many thanks in this case we now know that only the tacho would fit in the type 3 tacho housing the rev counter is to big to fit at all ! now i do need a tacho that is capable of showing over 180kph but i would need a way for it to not look stupid with my 80mm rev counter and fuel gauge that must stay!! any suggestions welcome.

You could always get custom gauge faces done and install them in your gauges. There is a guy that does them on this site somewere, I just can't remember his screen-name right now. It might be Phat73, post the question on the Interior forum if you are interested in that.