Here are some ancient shots of the tunnel opening and my homebrew tunnel cover from my NP435 days. No body lift. I used a trick I learned about from a 70's vintage Four Wheeler article about the NP435 swap, and flopped the t-case mount bushings top to bottom That lowers the transmission a little bit, just enough to clear. No body lift needed; there was enough room to r&r the transmission without problems. Having done it a few times due to unrelated clutch issues.
Eventually, I got tired of 3000 rpm at 70mph with 4.10 gears and 35" tires, since my Bronco sees a fair amount of freeway miles. I swapped in an NV4500 and changed the axle gears to 4.56; now I turn 2400 at 70mph, which makes my injected 5.0 happy. I do occasionally see triple digit speeds, but only on dirt roads. The Atlas that went in with the NV4500 takes care of the low speed stuff.
Eventually, I got tired of 3000 rpm at 70mph with 4.10 gears and 35" tires, since my Bronco sees a fair amount of freeway miles. I swapped in an NV4500 and changed the axle gears to 4.56; now I turn 2400 at 70mph, which makes my injected 5.0 happy. I do occasionally see triple digit speeds, but only on dirt roads. The Atlas that went in with the NV4500 takes care of the low speed stuff.