your thoughts

Howdy neighbor!
No problem.
Stock street suspension, or race. Springs and slicks are bolt-ons right?
The Dc manual says 12.4s require a Power to Weight ratio of .100 with race suspension. Street suspension may be up to a half second slower, due to the 60ft challenge, and the 3.21s.
So back to the .100 p/w
How heavy is that car? let's say you get it down to 3500 race weight. Well then; 3500 x .100 =350horsepower. The Dc folks work off crank power so, 350 is the target. Lessee 360 cubes,350 hp, that's .97 hp per cube. Ok maybe that's a lil tuff with bolt ons.
Since these engines seem to be 245 hp factory rated, we need 105 more hp, to just sneak into the 12s with street suspension. So I think we better bolt in some springs, gears and slicks. That reduces our p/w requirement to about .086, to just sneak in there.
Ok then 3500 x .086 =301hp; now yer talking.
This is doable with just a few other changes
This combo wants to hit a hair over a hunert so 4.30s are the go to gear. They will get you 102 at 5500 with 88s(28 inch tires) and 5% slip.
The 5500 trap points to a power peak of about 5100, and that points to 340 cam. Go get'em!
Arm-chair at it's finest, just suck it out of a book.

Your say he needs 350 hp and is 105 hp away from whats needed cause the stock hp is 245 hp. The only problem I see with this is there are two different ratings going on here gross and net. The 360 probably makes closer to 300 gross hp so he's only about 50 hp off his goal.