[robbo266317]

I'm assuming you have the capacitor in line with speaker and the inductor across it.
So your inductor works out at 40 mH for a 50Hz cutoff.
With a 3300 uF capacitor it's cutoff is now 14Hz - way too low for an 8" speaker.

You really have to know what you are doing when you change crossover components as the load seen by the amplifier can get really scary and changing the ~200uF to ~3000uF could explain the reason the amp is getting hot.
We really need to know the inductance of the coil to work out what the true story is.

 

[robbo266317]

I am assuming this is ported as well.
I cannot find anything when I search for info. Do you have any specs for it?
You need to have the high pass filter set so the sub doesn't get anything below the port tuning.

 

[robbo266317]

You will need to find a way to determine the port tuning.
Do you have a mic or spl meter? or can you borrow one.
If so you can use REW to measure the port output.