Anyone run high-flow Cats to reduce hydrocarbon exhaust smell?

FWIW,
I ran the 292/508/108 cam in my 367 at 11.3Scr.With 1.6 arms the lift was closer to .540. This cam in this small cuber did not like to idle very low with a 750DP-AG and TTIs. But with the correct or reasonable advance, it would free idle at 700, and I could pull it down to a bit under 500 with the clutch, and it would pull itself around a flat level parking lot with a 10.97 starter gear. She produced none of that eye-burning exhaust stink at all with the 76* of overlap.And no MSD either.And on 87E10.
The cure With these 250@050 and smaller cams is almost always in the T-port sync/timing.With maybe a little bit of bleed work. My cylinder pressure was around 175. But I run a minimum water temp of 205*.My squish was .022 +/-.002. I ignore the AFRs at idle giving the engine what she wants/needs to make her happy.
-I have come across this eye-burning stink in many engines when the T-port was out to lunch because the owner was scared to crank in some timing. About 5 minutes later it would all be gone. Unless the pistons were too far down in the hole. Then the lack of squish wants a bit more rpm. And if the TC is too tight, it comes back when put in gear.
-Sometimes if I don't start the fire early enough, the charge is still burning when it leaves the chamber.If it finds fresh air there it messes up the O2 reading. If you start the fire too early it works against the crank,and the idle has to be raised to compensate, and maybe not all the burned charge wants to leave. This is where an old fashioned dizzy comes in handy; you can just tug it this way and that and let the engine tell you what it wants. But you have to be careful cuz occasionally they will try to fool you.
-A lot of times the TCs are just too tight. Jack up the rear, put it into gear and ride the brakes until the stink comes up. There's your proof. More timing and less throttle may help. But it can initiate a hesitation, so then you work on pumpshot, and transitions. In the end a looser TC is probably a better solution.
-I wasn't paying attention to what heads you are using, but the lack of swirl in the factory LA open chamber heads seems to aggravate this stink
-The problem is not the late closing intake. Nor the overlap. Unless you are trying to idle it way too slowly, and your header pipes are pulling unbelievably hard, which I can't see with a full exhaust (I have full 3 inch duals with Dynomaxers)..You are probably idling a little lean, too, as others have mentioned.
-I work exclusively with carbed engines, so, I always attack the T-port sync first. Smaller cams seem to have less of a problem with this. I always figure it's a rich idle;possibly due to lack of T-port sync, and/or lack of timing; and that's how I get rid of it.Smaller cams don't need as much correction as the 250s.
--With EFI, and quench-heads,it should be a breeze to get rid of it. Not sure what could be bothering your combo, except maybe the cylinder pressure.or the chamber temperature that goes with that hi cylinder pressure.or the chamber shape.
Sorry I couldn't be more helpful