Make sure the baseplate to intake is sealing properly.....square to spread.
https://www.edelbrock.com/square-bore-to-spread-bore-adapter-plate-100-thick-for-edelbrock-manifolds-2732.html?srsltid=AfmBOopH3awVwySfM2rVppmLU0xSRvI-cNG2wxLoY9UEguog9TL1oBGu
Sounds like the "old" Hemi grind .471/.474 109cl #3690213. My buddy had one years ago in a 70' Duster 340 that was all stock, factory converter, and 3.23's. A little soft down low, but went a hair over 100mph in the 1/4.
Mopar Engine Cam Chart
Several Years ago a 10.0 Super Stock racer was chasing a similar issue and found nothing visual in the rear suspension. Finally did the go-pro thing as mentioned above. Revealed the threads on the pass. side front hiem were stripped and the bar was pulling out almost a inch on the top half on...
Very sad news. A strong, pretty woman with a heart of gold certainly didn't deserve this. Such is life i guess and i hope you rest in peace knowing how much you were loved here on earth. Prayers sent to Mallory, Billy and the entire family in this tough time.
Not knowing anything about your combo...I'd consider this one...
PLYMOUTH Howards Cams 718001-09 Howards Cams Rattler Camshafts | Summit Racing
With a mild combo it will be a little soft on the low end, but from a 20/25 mph roll, it'll pull like a bear to 5500/5800...