I installed a Hemi in my 70 Duster 40 years ago. Standard valve covers, no k frame spacers, Hooker 2-1/8” race headers, trimmed the steering column jacket, used the std. master offset adapter, notched the k frame for the race pan, and used the same technique Hurst did on the 68 cars for the shock tower - used a BFH. I did notch the steering box and moved it over a tad for more header clearance. That’s it.

Handled like a dream at 10 0’s and 133.