Just picked this reel up for a awesome price, I plan on using it for musky. But I've seen a lot of people use the Cardiff for big bass swimbaits, is this reel to big for a bass rod? I have 80ln braid on it but will run a 18" 140lb FC leader on it for muskies just in case. Anybody use the 400 size? Or is it overkill? How's the casting an drag on it?

TYG

I don't have the Cardiff but I have the Calcutta 400B that I use for muskie and big cats and occasionally swimbaits for bass. It casts very well and the drag is smooth and will stop any bass you'll ever hook. IMO it isn't too large to use for swimbaits for bass. 

i used to use a cardiff 400 for a few years and it held up great to snook fishing and i used 65lb braid on it...drag was always smooth and strong and it casted awesome...i used 1/2 or bigger with it and it would cast baits further than i ever needed 

When I started fishing swimbaits I had the 300 and 400 Cardiff's.  They are budget priced large round reels but from their performance you would not know it.  I used the 300 for medium swimbaits up to 6oz baits and the 400 for larger baits.  They are great reels for their price and are built like a tank.  The 400 should give you years of service even throwning the big heavy baits.