[Mike C]

A TH200 4R can be built to take the power and has a better gear split than the TH700R4. Along with 3.73 gear will be a beast out of the hole and on the highway.

The 4L80E can be built to take big power but factor in the $$$ of the electronic controller and it gets pricey.

Hot Rod drag week cars mostly run TH400 with Gear Vendors overdrive on the back. No electronics to deal with.

Running a non-lockup converter and a TH200 4R is my plan behind my 427 I'm building for my short step. I'm guesstimating 450hp and 550tq. Most likely I buy from Bowtie Overdrives but other vendors are out there. I even found one that had lifetime refreshes for $550. Something to consider.