Following a cool down, the Moroso Evac Pump Kit was installed, and the car was back on the dyno for testing. At idle, the three-vane Moroso pump pulled 1/2 inch of vacuum. Recorded at the same 6,000 rpm in Third gear, the pump generated 9 1/2 inches of vacuum and achieved an outstanding gain of 14.5 hp over the baseline.
As compared to the standard kit, the Moroso kit was able to pull out almost double the volume of pressurized crankcase gases, allowing even better ring seal and elevated horsepower numbers. Once again, the reduction of crankcase pressure kept any oil from escaping the engine.
| CONFIGURATION | AIT | IDLE VAC | MAX VAC | HP | GAINS |
| Baseline | 103.6 | 0 | 0 | 340.7 | N/A |
| Butler Std. Evac Kit | 109.9 | 0 | 5 | 346.6 | + 5.9 |
| Butler Moroso | 105.8 | 11/42 | 911/42 | 355.2 | +8.6/+14.5 |
| Three-Vane Kit |
 The supplied drivebelt that...  The supplied drivebelt that is matched to the 3-inch crank pulley and 5-inch pump pulley is slipped over the crank and pump pulley. Once the belt is on, the pump is pulled outward and a 9/16-inch wrench is used to tighten the two bolts. |  With the pump mounted, the...  With the pump mounted, the braided hose that goes from the inlet on the pump to the valve cover is hand-threaded on and then tightened securely with either an AN or adjustable wrench. |  The 90-degree elbow is removed...  The 90-degree elbow is removed from the outlet side of the pump, and the braided hose is threaded onto the pump and breather tank before being tightened. |
Drag Testing
Drag testing was conducted at Redline Raceway in Caddo Mills, Texas. Redline raceway is an eighth-mile venue, and on this day, it was hosting a bracket series held by the Texas Muscle Car Club Challenge. As George Reaves routinely laces up his spurs as a member of the Dallas Area Pontiac Association, the other member clubs in the Texas Muscle Car Challenge were happy to put aside their brand biases and allow testing at the conclusion of the bracket race.
George Reaves' (of Whitewright, Texas) '65 GTO is a former "Pontiac Pavement Pounders" participant, and the same combination of parts routinely puts the GTO into the 11.1-second e.t. bracket in the quarter with 7.2s in the eighth-mile. Powered by a '71 455 with round-port H.O. heads, the 12:1-compression engine uses an Ultradyne roller cam and Harland Sharp 1.65 roller rockers. Intake duties are handled by an Edelbrock Victor manifold and Holley 950 DP carburetor before dumping exhaust out of a set of Hooker headers.
An Art Carr 2,500-stall torque converter sends power through a Turbo-400 transmission and out back to a 3.90-geared Ford 9-inch rearend. ET drag slicks that measure 10.5x29x15 fill up the wheelwells.
The engine is shifted manually at 6,000 rpm and goes through the traps in the quarter-mile at 6,100 rpm. When run on an eighth-mile track, the car is barely able to shift into Third gear before the eighth-mile marker lights are tripped.
At the conclusion of drag testing, the difference in e.t. and mph between the best runs that were produced by the Moroso pump and the slowest runs without any vacuum pump were at or less than 0.04 in e.t. and 0.11 mph.
As expected, the short eighth-mile distance really didn't highlight the enhanced horsepower that the vacuum pump allows the engine to make, but more importantly, both units proved that they were the solution to stopping the oil leaks that would show up on the car at drag-racing venues. In addition to a clean engine compartment, there was no oil to be found on the bottom of the transmission pan, and the rear main seal was perfectly dry.
 After a final check to make...  After a final check to make sure the pump is secured, a vacuum gauge is hooked up to a vacuum fitting that Butler Performance welded into the valve cover for testing. Having such a provision is very important as it will not only allow you to register vacuum at idle and full-throttle to tell how much vacuum is being pulled during installation. |  The completed Moroso Evacuation...  The completed Moroso Evacuation Kit looks great hanging on the front of the GTO race motor and should provide years of reliable performance. With installation complete, it was time to test the results of the pump on the dyno. |  |
| Configuration | Temp | 60-ft | 1/8 ET/MPH |
| No Pump | 82.0 | 1.57 | 7.236/93.89 |
| 1.58 | 7.231/93.95 |
| Butler Standard | 82.0 | 1.58 | 7.213/93.99 |
| 1.57 | 7.216/93.92 |
| Moroso | 82.0 | 1.57 | 7.193/94.02 |
| 1.57 | 7.191/94.00 |
Recommended Tools And Supplies
Standard socket setStandard wrenchesAllen wrenchesCut-off wheel or fine-tooth hacksaw blade for cutting stainless braided hosesVacuum gaugeLoctite