There are aftermarket sheet metal inner fenders for the AD truck - here's a pair on ebay
https://www.ebay.com/i/142433449704?chn=ps
With those header's wrapping around the steering shaft you'd have to modify some stock inner fenders quite a bit to get them to clear (that's what I did)
My truck uses stock pedals with a hydroboost under the floor, so I'll leave it to the S10 guys to comment on the firewall pedal options.