Flexplate 153T SFI External Balance 86-up

The Flexplate 153T SFI External Balance 86-up by Allstar Performance is engineered for serious engine builders and restorers working with late-model domestic powerplants requiring external balance configurations. This flexplate serves as the critical coupling between your engine's crankshaft and transmission, designed specifically for vehicles from 1986 onward that demand external balance compensators. Whether you're rebuilding a classic carbureted big block or modernizing a crate engine swap, selecting the correct flexplate specification is non-negotiable for harmonious engine operation and transmission longevity.

This 153-tooth flexplate is manufactured to SFI Foundation specifications, ensuring it meets rigorous safety and performance standards for high-horsepower applications where component failure poses catastrophic risk. The external balance design means the crankshaft itself is balanced, requiring a complementary external balance weight integrated into the flexplate rather than internal counterweights. The 153-tooth count is engineered to work seamlessly with standard automatic transmission starters, providing reliable engagement across varying load conditions. At 6.1 pounds, this flexplate delivers the strength required for sustained power delivery while maintaining the precision concentricity critical for vibration-free operation across the entire RPM band.

Mechanics and engine builders favor the Allstar Performance flexplate for restoration projects, street machine builds, and performance engine installations where factory flexplates have become unavailable or obsolete. Proper installation requires careful alignment with your crankshaft's external balance provisions—verify your engine's balance configuration before ordering, as mixing internal and external balance components will result in severe vibration and accelerated wear. This flexplate pairs with SFI-certified flexplate bolts and torque converters designed for external balance engines, making it an essential component for anyone serious about bottom-end integrity on 1986-and-newer platforms.