No worries cali-horn-dancer, you can set your 1991 Volvo 740 turbo wagon up with a surfboard rack no problem. I suggest the
Thule 300 RainGutter multi-purpose roof rack base system for your raingutters. This system includes four Thule 300 Feet which attach to the raingutters, and also a pair of Thule load bars (make sure you get the 58 inch length bars for your 1991 Volvo 740 roof top). You can then attach the surfboard rack to the Thule 300 RainGutter base rack front and rear load bars. The
Thule 554XT surfboard rack is the best choice. The 554Xt attaches directly to the Thule 300 base rack load bars and can hold up to two surfboards. You will have enough room on your 58 inch load bars to attach a second 554XT if you want to carry a couple more surfboards too.