[bison]

AC drum is still GM's crappy steel. I twisted the splines on one myself. Others have had failure. The billet drums will not fail and dual feeding in your application is a must for direct clutch longevity. Use standard thickness steels in direct or thicker. Do not sacrifice steel thickness for more clutches. Trans-go is old tech. The accumulator valve in the vb is not touched in the trans-go kit. The spring on there is terribly inadequate. They also change a spring on one of the shift valves which is not a good idea imo. CK's latest recalibration kit is far superior to the trans-go kit. Trans-go pump rings are good. If you switch pumps you need very accurate measuring devices and a magnetic base grinder to clearance to spec (.0007-0015). You cant just swap out pump parts with new and slap it together. IMO the 10 vane is not needed. The 7 vane is good as long as its no grooved up. Just replace the rings. The Super servo works but it omits the cushion spring. A no no unless you want a clunking 3-2 downshift. CK's is larger and retains the cushion spring. I would build it non lock up and use a quality converter. You cant go wrong with PTC for quality vs. $ spent. Be sure to use one piece sealing rings on the forward drum shaft and the input to prevent cross leaks. Get clearances down to the minimums. The billet input, planet, and ring gear should be considered. If its going to make 650 hp you will be using that power some of the time. Otherwise why did you build a 650hp engine? The billet parts are very affordable these days and not worth skipping. You spent the $ on the engine no its time to back it up with a strong trans. Overbuilding a little will never hurt you in the long run. One shaft breakage, tow, aggravation from breakage, tear down time, parts replacement, and more more $ spent is no fun once you thought you completed a project and are held back and lightening your wallet more.