At 10.6, that cam and RHS's should be enough to get you running 11's. Might be tight on pump swill although your stuff is better than our California sacred goat pee.

Those lifters are good to around 7K... Don't be afraid to twist it, ask Brian. He also knows about another engine, as do you, that ran those lifters and a similar cam. It did OK.

tti Step or 1.75" headers will help some. I wouldn't put 1 7/8" headers on it. If 500hp strokers can't use 1 7/8" tubes effectively, doubt your mill will either.

Work on the front end of the car. There is some more in the 60's. You might try a shorter rear tire on it to get more effective ratio. It's got a 12.10ish in it based on MPH with a better 60' so you aren't that far off your 11 pass.

Keep jetting it up until it slows down, then back it off to highest MPH jetting. I don't think you hit that yet with the old mill, thinking it still had some MPH in it .