700R4 lock up kits

[1971ChevyTruck]

I found two different types of lock up kits. One is from Bowtie Overdrives which uses the brake switch to lock up the torq converter. Another kit uses the fluid pressure to lock up the converter. The fisrt one requires dropping the pan and wiring inside the trans. The second dosen't even require dropping the pan. Any one used either of these?? The prices are really close so thats not an issue. It just seems if like if I don't have to drop the pan I might be better off.