BIG difference between a 25-1/2 through 27'" tall tire compared to a 30" slick, will also completely change your power vs rpm range and shift points. Don't get me wrong in some cases (and power levels) you have to go from a 26" to 28" slick and for big power to a 30" and it's the right tire, but in other cases (and lower power levels) it can really mess you up and slow you down.
I ran 33 x 21-1/2 tires on one of my Prostreet Trucks and could spin them at will in any gear BUT the truck had close to 1000HP so it needed a tall wide tire. But when I put 30" street tires on a 9 Second Lightning I had it really really screwed it up. Shift points were way off and not matched with the power vs RPM range and I actually found it very sluggish so I went back to a shorter tire. When I put 28.81 x 12.01 Mickey Thompson ET Streets on my 03 Terminator I loved the look and traction they gave me but I do have to say it also changed my shift points to a point I didnt like. That had a Bullet Proof Pro Comp 4r70W Automatic with a Brake and 717 RWHP with a manual reverse Valve Body and very hi rpm stall so I was able to get away with it.
You do have two things in your favor, the 4.1 Gear and a Manual Trans but you still may find it a little sluggish off the line, longer to wind up, and dropping to lower rpm's after the shifts which can end up slowing you down at your power level. What Size Tire are you running now ???