Help me add 100 hp to a magnum 5.9 on a super tight budget

I have until Carlisle next year to have my dart running driving and faster than my kid brother sega (hyundai) genesis.
My car is a beater 70 swinger with a stock magnum 5.9. Spitfire headers,chinese(assault racing) airgrap intake,750 edelbrock with a 727 and an Assault racing stall converter. 8 1/4 3.23 gears the car came in boxes with the Chinese stuff and my budget is non existent so I used it.
The Genesis is listed at 348 horsepower and 295 lbft torque. So I'm over 100 hp down with a 245 hp magnum.
Can this be done with a cam,valve spring package and home cylinder head porting on the stock shortblock?
Can I make up the rest with Nitrous without exploding this thing? It has to drive four hours both ways to race.
I have almost a year to get it done but not much cash due to a massive remodel.

:popcorn: