ProTru by Wiseco 23 Degree Flat Top Forged Piston and Ring Kit - 4.060 in Bore - 1/16 x 1/16 x 3/16 in Ring Grooves - Minus 5.00 cc - Small Block Chevy PTS504A6 Engine Oil Centerforce Throwout Bearing N1493

Centerforce Throwout Bearing N1493

Up to 735 CFM

Mazda and Scion

It fits 1963-1975

Available in Youth 7X-Small to XS

ProTru by Wiseco 23 Degree Flat Top Forged Piston and Ring Kit - 4.060 in Bore - 1/16 x 1/16 x 3/16 in Ring Grooves - Minus 5.00 cc - Small Block Chevy PTS504A6 Engine Oil Centerforce Throwout Bearing N1493Chevrolet Small BlockWiseco Pro Tru is a division of Wiseco specializing pistons and piston rings for price conscious engine builders. They offer complete kits to fit a wide range of engines. Manufactured by Wiseco Performance Products, ProTru Forged Pistons are affordable with features usually found only in more expensive pistons. Product Description: Piston and Ring 23 Degree Flat Top Forged 4. 060 in Bore 1 16 x 1 16 x 3 16 in Ring Grooves Minus 5.