Howards
Grand National Street Roller Springs
1.437 Dia

Max Effort Mechanical Roller Valve Springs
Dual
1.437
1.080
1.080
0.796
175 @ 1.750
400 @ 1.150
375 0.625

Max Effort Mechanical Roller Valve Springs
Dual
1.500
1.116
0.800
170 @ 1.800
445 @ 1.250
480
0.700

PAC 1300 Series Drag Racing Valve Springs
Style: Dual
Outer O.D.: 1.500"
Closed Pressure: 250 @ 2.030"
Open Pressure: 614 @ 1.250"
Coil Bind: 1.180"

Pacaloy Mechanical Roller Springs
1.500 Dia.
w/Special Processing
250 @ 2.030
614 @ 1.250
1.180

Racing Springs
1300 Series 
1.500 OD
2.150 Install Height 
0.950 Lift
780 Rate
1.130 Coil Bind
Set of 16

Max Effort Mech. Roller Valve Springs
Dual w/Damp
1.539
1.125
1.015
0.731
194 @ 1.920
505 @ 1.200
510
0.720

Max Effort™ Roller Valve Springs
Style: Dual with Damper
Outer O.D.: 1.539"
Closed Pressure: 194 @ 1.920"
Open Pressure: 505 @ 1.200"
Coil Bind: 1.150"

Pro-Alloy Mechanical Roller Valve Springs
Style: Dual
Outer O.D.: 1.550"
Closed Pressure: 209 @ 1.900"
Open Pressure: 525 @ 1.300"
Coil Bind: 1.080"

Electro Polished Pro-Alloy Mechanical Roller Valve Springs
Style: Dual
Outer O.D.: 1.550"
Closed Pressure: 209 @ 1.900"
Open Pressure: 525 @ 1.300"
Coil Bind: 1.080"

Electro Polished Pro-Alloy Mechanical Roller Valve Springs
Style: Dual with Damper
Outer O.D.: 1.540"
Closed Pressure: 215 @ 1.950"
Open Pressure: 575 @ 1.230"
Coil Bind: 1.190"