powerglide vs th350

[hotrod 80]

I am about to make some pretty big ( in my world ) changes to my truck and im looking for opinions . The truck is a 1978 Chevy Luv with a 355 , th350 , Ford 9" 4.11 gears and a spool . I weighs as light as 2780 with me in it to as much as 3210 with me in it . I run a stock suspention , drag radial class that has a 410 ci limit and 3200# weight min . I also run a max of a 28" DR or a 26" slick @ the lighter weight . I will on rare occasions drive this on the street and it will keep current tags and inspection mainly for bragging rights . I will soon replace the 355 with a 397 SBC It should make around 600 hp + an 82 nitous jet ( around 230 hp) . I need a transbrake to be competetive in this class . I have a th350 that is in the truck that is fresh and works good that i could add a transbrake to or I also have a good powerglide with a cracked bell housing that already has a transbrake and works good . I have 2 other pg cases or could just have this one cut for an ultrabell bellhousing . Looking for opinions on which way to go and info on similar set ups .