Two speed TH400

[wrp]

Did a search and didn't find anything. Anyone using one? With my current three speed TH400 I am running our of gear on the top side, ie third gear. I have noticed that a lot of the 275 guys run two speed TH400s. I think a 1.58 ish first would help my twin turbos spool, but I am wondering what to look for to get a better topside. I am a complete novice at this.

Car is around 3700 lbs makes around 1250/1370 to the wheels with twin 62mm turbos on top of a 408 LQ9 built motor. Power goes through a FTi stage 5 TH400 and to the wheels through a ford nine inch with 3.56 gears and a strange S-Trac.

I have a couple of TH400 cores which is why I was thinking about building one as a two speed. I suppose the other option is a powerglide?