ERA427 Here's a short story, FORGET about HP. TORQUE is what moves the car. I had a 452 motor with great heads and an FI system. 4.25 bore and a 3.98 stroke. On a motor dyno it made 368 hp and 448ft of torque. Idle is smooth. TAKe 22% for drive train drain. The ERA side pipes are the best for a street car for noise control but leave some power on the table with too much back pressure at higher rpms. I odered a set of race pipes and picked up 26hp at 6,000 rpms. Torque did take a hit of 8 ft loss. How much time does a motor run a 6,000 rpms?? The motor rans low 12's in the 1/4 mile. 106-108mph.
It sound like you have a nice street car that is very mannered. Enjoy what you have and DON'T worry about what you do not have at this time. Down the road you may want to have more power, save this motor and build a nasty one. Over time if you do this you may find out that the bigger is better doesn't always work out.
Rick L.