I have run a blown 454 in a street legal T bucket (weighs 2500lbs before I get in and made 627 dyno'd hp @5800 rpm) for the past 5 years with a stout powerglide. Ran 10.2 in street trim. Couldnt break the trans, but I didnt think much of the manual valve body, but was told I couldnt get a normal valve body that could live behind my engine.

I have upgraded to a blown 540 and am guessing it will be north of 850 real hp. So I got another upgraded powerglide.

Its still a street car, but I made the mistake of getting a transbrake in the new trans. My tb button is on my steering wheel & its a bear when reversing and turning. I may yet refit the old powerglide trans.

In a light car a powerglide is just fine. In a heavier car the T400 is a better bet because the ratios are better - 3 is better than 2