Hey Jim. That's true. 4.56 gears aren't good for the road. But we drag race this car only. Actually, 3.23 or 3.55 would be as deep as you'd want to go. The 3.23's would keep the rev's down. Highway running with them would raise rpm's to about 300 to 500 rpms at the most. Car would have a really decent launch and provide both. No 4500 stall either. Something is about 2500 would work well. I've been fooling with MOPARS for years. I mean back in the early 70's. I also have a '71 340 Duster that I drag race. Full interior and all. .030 over 360 that runs 7.78's in the 1/8th mile. It's for drag racing only. 4.88's and all. I've got a '73 340 Duster that I bought new in October of '72. It has a 3.55 gear in it. Rev's at 70 mph at about 3200 rpms. I just love my MOPE's. A 318 though is often overlooked. They are strong motors.