For a street type car, a stock rebuild with good stock parts (like a new pump, all new bushings, etc) will hold things fine. If you add a manual valve body, the pressures go up. The stock frictions are OK, but you want to make fsure ther are enough in place. Some 727Bs have 4 friction clutch packs, some have 5. You can now buy 6 IIRC if you want to. The more frictions, the more surface area, the more surface area, the more power it can hold. You also want to be aware that the servos are simple cast aluminum. More pressure means more stress, and the servos can be a problem. The bolt in sprague is cheap, and always a good idea. But truthfully, the part you need to protect is the forward clutch retainer (or "drum", or "basket"). Billet steel will forever fix the explosion problem should the sprague get rolled and you dont look for it. (like when a ring gear breaks in 1st gear...). Billet aluminum is great for race cars, but it wears too fast for a street car. my "default" combo is stock rebuild with red frictions and steels, new pump, bushings, red bands, and a manual valve body, and sprague. Those hold 500hp on a street and street/strip with no issues. Next step is upgraded servos and the 4,2 lever, and a deep pan and good cooler. Next would be 5/6 disc billet steel clutch drum, and blue frictions, the servos, and the other stuff.
