18x9 wheels what tire size?

[aany001]

Need some help with my 69 camaro with a stock sub frame. I resized my front 18” rim to 9” wide. What tire size are you guys running? I was running an 18x8 with 245 40 18 and 5 1/8” back spacing. I was running 3/4” spacers up front and removed them and widened to a 9”. I had no issues except minor turning radius loss which I adjusted with my steering stops. So with a 1” wider rim removing the spacer and adding 1/4” negative camber I think I should be right where I was before. I’m thinking of going with a 255 40 18. Im looking for a flat sidewall with no bulge or stretched look. I hope all this makes sense.
Thanks in advance.
Steve