The Ultra Sprint billet crankshaft has been designed to meet the grueling demands of 410 and 360 Sprint Car applications. For improved performance and durability, primary counterweights have been thinned down reducing windage resistance while interior counterweights have been maximized to minimize intermediate (2 & 4) bearing loads. All Ultra Sprint billets feature the Callies Aeroshed surface treatment and are available in strokes from 3.300 to 3.825 with any variety of rod and main size configuration. Typical weight 3.800/400/1.888 = 44lbs.
| Stroke | Pin Size | Main Size | Part # | |
| 3.5500 | 1.8880 | (350) GM Small Block – 2.448 | Ultra Sprint Car | SAT-19@-US |
| 3.8120 | 1.8880 | (400) GM Small Block – 2.648 | Ultra Sprint Car | SA1929@-US |
| 3.8200 | 1.8880 | (350) GM Small Block – 2.448 | Ultra Sprint Car | SA1319@-US |
| 3.8200 | 1.8880 | (350) GM Small Block – 2.448 | Ultra Sprint Car | SAZ-19@-US |
The Ultra Sprint billet crankshaft has been designed to meet the grueling demands of 410 and 360 Sprint Car applications. For improved performance and durability, primary counterweights have been thinned down reducing windage resistance while interior counterweights have been maximized to minimize intermediate (2 & 4) bearing loads. All Ultra Sprint billets feature the Callies Aeroshed surface treatment and are available in strokes from 3.300 to 3.825 with any variety of rod and main size configuration. Typical weight 3.800/400/1.888 = 44lbs.
| Stroke | Pin Size | Main Size | Part # | |
| 3.5500 | 1.8880 | (350) GM Small Block – 2.448 | Ultra Sprint Car | SAT-19@-US |
| 3.8120 | 1.8880 | (400) GM Small Block – 2.648 | Ultra Sprint Car | SA1929@-US |
| 3.8200 | 1.8880 | (350) GM Small Block – 2.448 | Ultra Sprint Car | SA1319@-US |
| 3.8200 | 1.8880 | (350) GM Small Block – 2.448 | Ultra Sprint Car | SAZ-19@-US |