Probe PRS Series Pistons for the 400 Chevrolet Based Engines are manufactured on advanced 2618-t6 forgings; featuring forged side reliefs with internal and external bracing. Most feature double spiral locks (or wire locks in some applications), forced pin oilers with oil distribution grooves, and lock removal indentations. They also feature gas accumulator grooves in the second land and double forced pin oilers with oil distribution grooves, as well as optional gas ports. Locks, wrist pins, and lock removal indents are included.
Flat top pistons in a Chevrolet 400 to 434 engine will generally provide compression ratios in the 11.5 to 12.5:1 range which makes them a good option for competition engines with aluminum heads and larger than stock camshafts. Valve reliefs are configured to work with most types of standard and 23° aluminum cylinder heads and will normally fit camshafts to well over .600 valve lift.
Dish top pistons in a Chevrolet 400 to 434 engine will generally provide compression ratios in the 9.5 to 10.5:1 range which makes them a good option for engines with aluminum heads and larger than stock camshafts. Valve reliefs are configured to work with most types of standard and aluminum 23° cylinder heads and will normally fit camshafts to well over .600 valve lift.
Dome top pistons in a Chevrolet 400 to 434 engine will generally provide compression ratios in the 13 to 14.0:1 range which makes them a good option for competition engines. Valve reliefs are configured to work with most types of standard and aluminum 23° cylinder heads and will normally fit camshafts to well over .600 valve lift.
