One thing I'll add is if you change the gearing/tire size, re-calibrate the speedometer. I put 30" tires and swapped the trans for an O/D unit that was originally from a 4.10 geared station wagon. I knew that it was off, seemed to only be around 5 mph at 45 indicated. Well, a couple pf weeks ago, I took it out and decided to open the 235 up. Cruised nicely at 2500 rpm, 65 indicated, so I opened it up a little more. I held steady at 3000 rpm in O/D, 80 mph indicated. When I got home I ran the numbers to see how far off it really was. Turned out I was doing about 100 mph. Needless to say I ain't doing that again.
