We used the high-performance...
We used the high-performance Fel-Pro 1105 head gasket due to the high compression. This head gasket has a bore diameter that is a little larger than ideal for our bore size, but sometimes you just have to work with the parts that are available.
With the carb dialed in, we pulled the throttle lever and the big motor responded with a best of 630 hp at 5,600 rpm. The torque peak was 630 lb-ft at 4,700 rpm. So the change to a high-rise, single four-barrel intake picked up about 20 lb-ft and 20 hp over the dual-quad setup. That seemed about in line with our previous experiences with the Performer RPM intake manifold design, as it has always made really good power in this rpm range. A Mopar guy can't go wrong with either combination underhood. Both induction systems look great, and they both made excellent power for us.
| BY THE NUMBERS |
| 505ci Mopar Big-Block |
| Bore: |
4.350-inch |
| Stroke: |
4.250-inch |
| Displacement: |
505.3 ci |
| Compression ratio: |
12.5:1 |
| Camshaft: |
COMP Cams XR292 |
| hydraulic roller |
| Cam duration: |
242/248 degrees |
| at .050-inch lift |
| Valve lift: |
.584/.579-inch |
| Rocker arms: |
RAS 1.60 ratio |
| Piston: |
Diamond Racing, custom |
| Block: |
'74 passenger car 440 |
| Crankshaft: |
440Source.com 4340 forged |
| Rods: |
Scat 6.800-inch Chevy H-beam |
| Cylinder head: |
Edelbrock Performer RPM |
| Intake valve diameter: |
2.140-inch |
| Exhaust valve diameter: |
1.810-inch |
| Intake manifold: |
Edelbrock CH-28 |
| Carburetors: |
Edelbrock 1804 AVS (2) |
| Headers: |
Stahl 2x32 dyno headers |
| Distributor: |
MSD billet |