Probe 12336-030
Probe SRS Forged Pistons are made from forged 2618 T-61 aluminum alloy. The lightweight forging and low-drag skirt help provide quicker revs. The pistons are fully CNC-machined and use tool-steel wrist pins for increased strength. A pressure-equalization channel promotes ring seal to deliver more power. The oil drain-back holes are slotted to keep oil from gathering in the oil ring groove.
| Bore | 4.030 inches |
| Stroke | 3.750 inches |
| Rod length | 5.70 inches |
| Compression height | 1.425 inches |
| Compression | 10.79:1 (approx) |
| Style | Flat-top, 2 reliefs |
| Material | Forged 2618 alloy |
| Head | 64 cc |
| Pin diameter | 0.927 inch |
| Pin type | Floating |
| Top groove | 11/416 inch |
| Second groove | 11/416 inch |
| Oil groove | 31/416 inch |
| Weight | 489 g |
| Dome volume | -4 cc |
| Price | $532 |
Ross 90765
The Ross heavy-duty flat-top piston is designed for use with moderate amounts of nitrous (up to 250 hp). These pistons will work with both 22- and 23-degree valve pocket angles or Vortec heads. The two valve reliefs are machined to allow the use of a high-lift cam with large valve diameters. They also include forced pin oilers and aircraft-quality pins made from heat-treated material.
| Bore | 4.030 inches |
| Stroke | 3.750 inches |
| Rod length | 6.00 inches |
| Compression height | 1.133 inches |
| Compression | 10.7:1 (approx) |
| Style | Flat-top |
| Material | 2618 T61 forged aluminum |
| Head | 64 cc |
| Pin diameter | 0.927 |
| Pin type | Floating |
| Top groove | 11/416 inch |
| Second groove | 11/416 inch |
| Oil groove | 11/48 inch |
| Weight | 486 g |
| Dome volume | -4 cc |
| Price | $560 |