Which way to go?

[highboostgn]

Ok so I'm looking to upgrade my trans to hold 600-700hp. I've been looking at the stage 2 transmissions from Century and a few other places. My question is should I keep the 200r4 or switch to another trans like the 400? From what I've seen it looks more cost efficient

 

[SHADOWII]

I have Lonnie's stg III 2004r which offers a 4th gear if I want to go o.d. for h/way driving. something the 400 doesn't. I like the idea of extra gears like the 4l80 offers w/up to 6spds but creates a problem as stated by Dusty of the l/u converter. If 3spd's is all you need, you probably can't beat the 400. Although my stg III has been trouble free even w/ the swapping of l/u and non-lu.