Hi Dr bob, I've been told you might be able to help me with a small problem I've got, I have a 1997 VT exec 5L 5speed, and the factory tacho is inaccurate, it overestimates by a fair bit, by a few hundred RPM at idle and by 2-3k at the top of the revs, I believe a previous owner has put a V6 dash cluster in as a quick fix to shut up the next owner who wanted a working fuel gauge. I'm told it can be reprogrammed with a tech 2, or i can replace it with another cluster, if i choose to use another cluster, which ones are compatible? can I use a 3 window calais one? or a VX V8 one?