transom shield positioning

[irrelevant]

Hi,

I am about to mount the transom shields to my 36' HydroCat which has seen a succession of idiots butchering the original holes and which I have had to re-glass and build up. I have the correct template from Volvo Penta and want to get the measurements just so, however I am unclear as to whether what I'm doing would be considered a "single installation" or a "twin installation".

Would a single engine in a single hull of a cat be considered a single installation? or because I'm mounting two (one in each hull) would it be considered a twin installation. The difference in measurements is substantial.

Any help or advice would be greatly appreciated.

TIA

Paul