How much power can you take out of these engines with superchargers. Stock internal parts,they are Gen VI ,and what blowers are best to use.

850-900hp on pump gas...

700 long life h.p.

as stated above , with more freshen ups.

Any ideas what blowers, these are carburated engines.

B & M 8:71's

heres 2, first mad about 720, the second made 800.

700 is realistic , 800 to 900 not for long and you'll be putting some good parts back in

I have a 454 Gen V HP425 with a B&M 174 - is this block the same as the 500hp and if so does that mean its bullet proof (English expression for long life with abuse!)

Depends on your defination of "not for long" I know of several with over 100 hrs like that... Your point is well taken, they won't live forever that way....

One that makes 847hp....

You can make 650-700hp with 250 blower and single carb.