twisted minis
+1y
Your exhaust still has to go under the tranny crossmember. It makes it a lot easier than building it over the crossmember, especially if you're using larger exhaust. Even if you have a dump, thats generally behind the cab. Also if you're exhaust is going over the crossmember it will make your floor pan noticeably hot. I liked this design due to the fact that the exhaust could easily be pulled, which was convenient when building it.
And yes, your stock crossmember needs to be cut out. Can be done in about an hour with a sawzall. Unless you have a lift and get get a good angle on it, you could probably do it in about 20 minutes.
My tranny crossmember is bolt in, bolt out. BUT, you have to weld on the provided tabs. I've revised the mounts since I built mine. They come about 3/8" long so you can trim to fit. I've found that most Toyota frames are not the same, some are slightly wider, some more narrow. Most frames arent perfectly straight. So this allows you to get it right for your specific truck. But its very easy to install.
I haven't made the jig yet, but will be doing so soon.