Wait, a single 3" is too big, but two 2.5" for a total of 5" of exhaust for the same displacement isn't? You contridict yourself. Badly.

A large exhaust in and of itself doesn't cause a power loss anyways, exhaust sizing will shift the powerband up or down in the rpm range. Now, if you go too large, you'll shift exhausts optimum scavenging range well above the rest of the engines breathing capacity, and hence lose power.

But really, thanks for the advice.

3'' is not to big for the mods on that car ls1 camaros can run single 3'' no problem my 92' dakota has single 3'' on stock motor (318mag) and i'm not losing power.

3 inch exhaust is way to big ur losing power because of it get a true dual 2 1/2 best way to go i have a true dual 2 3/4 in my 82 camaro