Q&A WITH SHAWN MENDENHALL FROM COAST HIGH PERFORMANCE
CHP: We gave you a tough task, building a traditional small-block to match up with a Gen IV motor.
Shawn Mendenhall: GM did well in designing the LS-series engines. The 15-degree heads are such a huge advantage. It would have been nice if we could have used 18-degree cylinder heads.
CHP: It there anything to be said for going old school?
SM: The only advantage for the 23-degree setup is the bore. With a larger bore size, it's easier for the heads to breathe, and you can start with a factory block, which you can still get at a swap meet. It costs more to do a 4.125-inch bore in the newer motors, because you need cylinder sleeves and custom pistons.
CHP: What does the future hold for the traditional small-block configuration?
SM: Until there's no more gas, people will have fun with them. As long as there's a desire for 23-degree parts and people still have stuff stashed in their garages, they're never gonna go away. Aftermarket blocks are more within the average guy's reach.
CHP: You mentioned 18-degree heads. What are your thoughts on the subject?
SM: The 18-degree stuff is old-school racing technology. Make it user-friendly, which is already starting to happen, and it's gonna really change the market. You can make good power with 18-degree heads--they're gonna be able to make a ton of horsepower on the street.

Cam I
Headers13/4 Hedman long-tubes
Fuel91-octane unleaded
Advance39 degrees
Max torque @ rpm533.0 lb-ft @ 5,000
Max power @ rpm576.4 hp @ 6,300
Average torque 485.6 lb-ft
Average power430.8 hp
RPMlb-ftHp
2,600401.4198.7
2,700399.0205.1
2,800398.7212.5
2,900401.7221.8
3,000408.5233.3
3,100419.6247.7
3,200433.7264.3
3,300445.4279.9
3,400456.3295.4
3,500465.6310.3
3,600473.6324.6
3,700481.0338.9
3,800488.6353.5
3,900495.4367.9
4,000501.0381.6
4,100505.4394.6
4,200510.0407.9
4,300514.4421.2
4,400518.2434.2
4,500521.7447.0
4,600525.5460.2
4,700529.1473.5
4,800531.5485.7
4,900532.8497.1
5,000533.0507.4
5,100532.2516.8
52,00530.5525.2
5,300528.4533.2
5,400525.7540.5
5,500522.5547.2
5,600519.2553.6
5,700515.1559.1
5,800510.5563.8
5,900505.6567.9
6,000500.7572.0
6,100493.8573.5
6,200487.2575.1
6,300480.5576.4
6,400470.9573.8
6,500456.4564.8
6,600441.2554.5
Cam I with 1-inch HVH Spacer
Headers13/4 Hedman long-tubes
Fuel91-octane unleaded
Advance39 degrees
Max torque @ rpm532.7 lb-ft @ 5,000
Max power @ rpm582.9 hp @ 6,300
Average torque 484.8 lb-ft
Average power430.9 hp
RPMlb-ftHp
2,600386.3191.2
2,700386.0198.4
2,800387.1206.4
2,900392.7216.8
3,000403.6230.5
3,100417.9246.6
3,200432.6263.6
3,300445.0279.6
3,400456.0295.2
3,500465.6310.2
3,600474.5325.2
3,700481.5339.2
3,800487.8352.9
3,900492.9366.0
4,000497.8379.1
4,100502.4392.2
4,200506.8405.3
4,300512.1419.3
4,400516.4432.6
4,500519.8445.3
4,600523.0458.1
4,700527.6472.1
4,800530.8485.1
4,900532.3496.7
5,000532.7507.2
5,100532.5517.1
5,200531.8526.5
5,300530.1535.0
5,400527.5542.3
5,500524.0548.8
5,600520.2554.6
5,700516.3560.4
5,800512.3565.8
5,900507.4570.0
6,000503.1574.8
6,100498.3578.8
6,200492.3581.1
6,300486.0582.9
6,400477.1581.3
6,500462.4572.2
6,600446.1560.6