Motor mods are fun arent they lol

Mild 408 strokers get around 310+rwhp.
Yeah, have to agree, around 240rwhp I would say(around 300crank). That blower should help matters
If this is a fresh motor, it will be a bit tight.
Cam could be off a tooth.
More than likely the sync between the crank shaft sensor and the camshafts sensor is off. When I put mine in (rt+10/m1) same thing, it was just horrible. Took it to my parts guy down the street cause I knew he had a scan tool. When we checked it was retarded 4-5degrees. Little tweak of the distributor till it was at 0. KRC says they advance it 6-8 degrees with their cams. I would suspect for na engines it would be fine. Blower in your future set it at zero degrees cause your going to have to pull timing anyways(or n2o).
You could still use a couple things more as others mentioned
High stall torque convertor is a must, go with 2400 min.
Gears, bump them up, you want a 410 or higher final(if you dont already cant see sig)
1.7 roller rockers will give back some of the lost torque as well. The total lift would be .510/.510 with the higher ratio.
As far as a tune goes.
You could get Mike Leach at B&G Chrysler to do a flash on your stock pcm but that would mean your trucks down till it returns. The flash isnt cheap but I think you get one free update (for blower

) so it may not be a bad deal. Maybe get one off ebay and send it in.
Other route get a piggyback tuner like I have now, or a full standalone managment like the PR8 or FAST setups.