Sounds like a lot of mismatched parts and/or multiple issues, not just one thing. 10 years ago my Dads 2700 lb Malibu ran a 9.80's @ mid 130's with a 406, Pontiac 867 heads, bowtie intake with an adaptor and a Dominator, the same cam you run, 32" tires with a 4.30 gear, 8" 5500 stall. He ran 11.30's with a dish piston 406 on pump gas, 461 heads, and a FT cam in a 3100 lb Camaro.
Your 1.7 short time is a killer, something going on with traction that you may not realize. I would have someone take some video's.