I run the street dominator with a 1" spacer and it fits under the hood of my 63 with no problems. It fit fine even when I had the flat hood on it. And the street dominator works great. It has good low eng and top end. My 63 goes 3700 lbs and has hit a 1.57 best 60 which is repectable for a mid 11 car. My son has the RPM on the 400 in his Dart and he loves it also. We ran a street dominator on his 400 and compared the two intakes. He went 11.59 @ 117 with the SD and 11.55 @ 116 with the RPM. The RPM was a tad better down low but the SD had more mph. Very close.
Here is the SD on my 440 in my 63. Ron