trailer help

[tautog_33]

Hello everyone I am a junior member purchasing my first potter built seacraft. It is a 20 MA 1979. The boat is in the water and has no trailer. I have purchased a new trailer for the boat it is an aluminum bunk Venture trailer G.V.R.W. 3185. I have read on other threads that the bunks should be lined up with the stringers. The trailer doesn't have any keel rollers all the weight will be on the bunks. The reason why i posted was to see if anyone else has a similar trailer or could give me a rough estimate where i should have my bunks positioned. I am looking for a measurement from the center line of the keel to the inner side of the bunks. I would then take that measurement off the center line of the trailer and hopefully be really close. Any feedback on this would be much appreciated. Thanks!

P.S. I will be posting pics of the boat soon.