I'd think you have enough to overwhelm a typical 8" mopar converter. Sounds like you have a 9.5"? ...put that in!!! There's gotta be some low hanging fruit for loosing weight in that car? Sounds like you have a nice engine, I'd put some time into loosing weight before I stepped-up the engine anymore. If noting else, you brakes will thank you.
Biggest weight loss would be swapping out the cage to a CM one, it's not even a CDS one, it was made out of 1 3/4" steam pipe front to back. The tech guy was amazed how thick it was, even on the outside of the bends
I'd guess swapping it would save 150 to 175 lbs but the cost
. I also got it re-certed last time out and tech'd so we got another 3 years on every thing.I have a big 'chute as well but the car stops well just on the brakes only used it about twice just to see if it works.