3/8" diameter push rods, NOT 5/16". Studs are 7/16" Top & Bottom Includes (8) Overall length: 8.281" Push Rods Includes (8) Overall length: 9.254" Push Rods (8) 3/8" Slot stepped guide Plates (16) Black Oxided 190,000 PSI Alloy Steel Studs This listing is for a brand new stock replacement style pushrods, guide plate and rocker arm stud kit that is made by Elgin Industries. Kit includes 16 pushrods, 8 guide plates and 16 rocker arm studs. These are compatible replacements for Chevy 396 CID (6.5L) 1965-1970 Passenger Cars & Pickups, 402 CID (6.6L) 1970-1972 Passenger Cars & Pickups, 427 CID (7.0L) 1966-1969 Passenger Cars & Pickups & 454 CID (7.4L) 1970-1990 Passenger Cars & Pickups Note: Some Chevy big block engines came with 3/8" diameter push rods like these. Others came with 5/16" diameter push rods. Please be sure yours are 3/8" diameter. (8) PR441S+(8) PR442S+(16)RDS-941-16+(8)75-107