Trailer Bunk Guide ons (what size?)

[jeepnsam]

So...decided to use mothers day to change out the trailer bunks at the local lake.
Launching and Retrieving with the wife and 6 month old baby is NOT THE BUSINESS!

I think adding the guide on's will make the process less stressful.

QUESTION:

Will the 2' (one post) bunk guide-on I see (1 left) on iboats work my my 18' deep v searay with the heavy v8????