low,, what kind of rpm's are you turning now through the traps? (with what tire your running now?)
Or you can look at it this way. A 200 HP shot might give you a .5 or .75 second improvment,, )more if your currently running 14's less if your currently running 10's obviously) Let's assume with 300 RWHP your going to turn mid 12's, with the 200shot mid 11's. A typical mid 12 second ride is going to be in the 110-115mph range. 115mph with a 10% loss through the convertor, a 28" tire and 4.10 gears will put you at about 6200rpm in the traps. If you were really light and quick already and trip the timers at a mid 10 (and typically around a 122-128mph) you would be at 6700 with the short 28" tires. My thought is,,, if you have a 350 tolerant of a 200 horse shot, you surley have a 350 capable of 6700rpm, or even 7000. Then your only problem becomes gear multiplication on the starting line putting so much leverage on the available traction, that you blow the tires off.
Taller wider tires will help your statring line traction and make chassis tunning a little easier (simply because your not overpowering the tires). Myself, I'd start with the taller tire and add more power as needed to run on the ragged edge
