well, i just learned today after hours of reasearch that my merlins that i were told when i bought them were 310cc intake runners, are infact 345cc intake runners!!! on a pump gas 496.. could this have alot to do with throttle response and low end torque issuses? Im thinking now to pull em' sell em' and get a set of merlin oval ports..
Need some input

 

Big heads on a sub 500ci NA motor definitely hurt throttle response/low end torque. If you don't turn beyond 7k rpm, they don't even make any more peak power.

I would really look into swapping to some aluminum heads. You could bump the compression considerably and still be pump gas friendly, plsu the large amount of weight removed from the nose of the car. Edelbrock has some street oriented aluminum oval port offerings.