It won't cause problems to do just the 1-2 and 2-3. You don't really need a firmer shift at WOT during the 3-4 shift. How fast is that? Well, with my 3.69 FDR, I shift at 5000 rpm at about 110 mph. With a 3.29 that would be about 123 mph, and since you guys usually shift at 5800-6000 rpm, that would make it about 145 mph. Usually, when driving, the 3-4 shift in most cases isn't much over 30-40% tps, and that's more of a highway acceleration shift. So you won't be getting into much more line pressure for a firmer shift. I already have the side cover, valve body, and channel plate off, so no big deal to throw in the 3-4 revisions.
