V-Belt sixes for 1988 290xf

[George290]

I'm new here and recently purchased a 1988 290 xf.  She has twin 350 ci. Crusaders.  Does anyone know the proper size V-Belts for these motors?  The belts on her are too small, as I found out while doing some PM.  I could just move up a half inch or so in size, but figured I would see if anyone knew the proper size.  Pics to come soon as I get around to it, everyone loves pics.