HP on a stock 4l80e

[540' chevelle]

How much HP does a stock 4l80e hold? I have a 540 in a chevelle with a manual valve body th400 and I love untill I get on the highway and them I'm in pain!

Found one at a truck yard for $500.00 looks like a deal. But I have some questions.

1. How much HP can it handle stock.
2. Will my flyweel work.
3. What manual ratchet shifter will work with this trans.



Thanks