has anyone used these to mount bunk boards ? They mount to the frame with a u-bolt and there is a top pivot piece to mount the bunk board to.

http://shop.easternmarine.com/index.cfm?fuseaction=catalog.prodInfo&productID=5233&categoryID=223

http://shop.easternmarine.com/index.cfm?fuseaction=catalog.prodInfo&productID=5728&categoryID=223

would they be strong enough for a 19 ft aluminum boat with a 115 ?