I have a 1969 Chevelle, and I have always run 15x8 Ralley wheels w/ 235/60/15's up front and 275/65/15's in the rear. I have just been given (2) 15x7 American Racing Torque Thrust D's from one of my friends. I still need to purchase wheels for the rearend. Question is, "What will fit?" I was looking on Summit at 15x8.5 w/3.75 backspacing. Will they fit, and what is the biggest tire I can run?

I would stick with your original plan and run 275/60-15's but you need a 15X8 with 4.5" backspacing not 3.75.

Dave

a 15x8.5 with 3-3/4 backspace will fit on a 69... It's the tire selection that will cause problems. A 245 section width should clear the fenders ok. A larger backspace, as Dave427 suggested will alleviate these clearance problems and allow you to run a wider tire.