Just purchased a 496ho with stainless marine exhaust. Was $5500 a decent deal?

New? I paid $14000 (installed) for a new 496 Mag HO in 2004, so yeah if it's new you got a deal.

I would be surprised if that is the price for a new one. Time will tell if it was a good deal, or not.
A lot depends on condition and how the hours of use were put on the motor. Was it ever run hot ?
Was it run at WOT for the full time, or was it run at 2500-3000 RPM for the majority of its lifespan, with the odd burst of WOT ?
And what about maintenance ? Frequent oil changes help.
Do you know why the engine was removed, and how many hours were on it ?
Being able to trust the guy you bought it from means a lot as well. Hopefully he was honest and up front with the whole story about the previous life of that engine.

Did you run an engine scan with a Rinda?

If it is in good running condition then yes, you got a really good deal.

any deal and price - really needs to be deeply examined - how many hours, how well of maintenance has been done thru out the years, scanned for run times and hours, compression equal and good enough across the board, corrosion issues & factors, whats not stock and whats not right about any installs - past work that has been done by whomever (many hack jobs out there ) , fuel pressure reading while running and so on for a jist.