Single Plane intake question

I must be the exception to the rule but, I have had an M1 on my 440 for 12 years now. I had the car dyno'd when it was just a .030 over 440 with stock 906 2.08/1.74 heads, a .484 MP cam and M1 with 800 Holley and it made 511ft. lbs. at the tires. I just finished a slight rebuild where I changed the cam to a solid MP .557 and put on stock edelbrock heads and Proparts headers. This car is an absolute beast now! I have never even questioned my 16 year old mind picking that M1 twelve years ago. The car is a 3200lb 73 Duster with a Dana and 3.73 gears, manual 727 and 3500 converter.