What wieght oil do you use?

I use 10W-40 Castrol GTX in ny 340 and also add Lucas oil additive. My car is only driven to shows and cruises and I stay off Interstates and use 2 lane black tops to avoid high unnessary rpm's and also to enjoy the country side, so that would probably seem odd to ya all but with the 4:10's in a pretty much stock motor Im trying to avoid high maintenance.