200 WHP means you need around 230 Crank HP. (aprox 15% drive train loss with a manual). 230 HP. Stock is around 140 HP at the crank. Simple math tells us that you need to gain 90 HP in mods. With bolt ons, this will be VERY hard to do, yet very costly. Can it be done? I would think so, but its a long, hard, expensive road in doing so. There is no way in hell a set of cams will yeild 50 HP, at least no on the 420A. You have to realize that the 420A in stock form, is already tuned, and valve timing, and camshaft profiles are already up to par pretty well. You can def squeeze more HP from this motor NA, but gains will NOT be 50 HP per mod for cams, or whatever. You will NOT gain 35 HP from a ported intake and head. It just wont happen. Porting on big V8 motors give sizeable gains, mostly because they use carbs, and the entire A/F mixture is coming from them, and travels through the entire intake manifolds. This lets them flow more A/F into the cylinders. With our motors, enlarging the ports is somewhat insignificant, but does help slightly, mostly with the power band/torque curve. You actualy prob wont see much, if ANY HP gains from porting on these motors. A big problem from this is because these motors use a MAP sensor, not a MAF(mass air flow). MAF sensors would be a much better way to measure the amount of air going into the motor, and would prob be a much better way to utilize the added airflow of porting. IMO, a MAP sensor just isnt that sensitive to small gains in airflow. Here are more realisitc gains, in CRANK HORSEPOWER

Ported intake and head- ~10 HP
Aggressive cam- ~ 15-20HP
Raising compression ~10-15HP
UDP- ~5-7HP
CAI- ~3-5HP
ADJ cam gears- ~5-7HP

Thats a basic list of popular NA mods
The total adding onto the stock 140 CHP=

204 CHP. Now, take the 15% drivetrain loss=

173.4 WHP I think this is a very attainable power figure. With some aggressive fine tuning, 180 WHP could be possible. Anything above that, will be VERY hard to do. You have already done most of the big NA power adders in this list. Even so, 180, even 200 WHP, in our 2800+ pound cars, will not be all that fast...Start stripping the car to lose weight, and it becomes less and less of a street car. Its going to already run like shit at idle with the large cams and port work.... And another thing, dont just say you will get around "this much" wheel HP. We can all speculate all day long, but it doesnt mean shit until you actually put the car on the dyno, and get your results. The numbers I have posted here, are pretty accurate numbers, from dyno sessions I have been involved with, on these motors.