20 Inch Tire Pressures

[basketcase]

I have this '84 in my shop that a friend bought last weekend at the RM Sotheby's Fall Auburn auction. I'm fixing a few items on it, just some odds and ends that didn't get finished during the repaint. It's a low mile rust free Georgia truck with all the options. Engine is a 305 4bbl and it is a real nice truck. No mods to the driveline.They said it's lowered 5 and 7. Wheels are American Racing 20x8 and 20x10 as best I can measure on the width with 245/45 on the front and 275/45 on the rear.

I haven't been able to find the recommended tire pressures for these tires. Maximum pressure is 49psi. I'd like to know what pressure members with these tires run.

Thanks
Tom