On the shelf and in stock! These 4340 steel connecting rods are an exact replacement for stock M57 connecting rods with factory pistons. Made 100% in house in Johannesburg Michigan on our cnc's with Ampco-45 small end bushings supplied by PPP Center. These are designed to be the strongest rods available period and hold well in excess of 1000hp. We have one discounted set of M47 rods in stock with a minor cosmetic blemish on one rod. 

The bolts included are 3/8"-24 x 1.5" genuine ARP in their ARP2000 alloy. Bolt torque spec is .0055-.006" stretch or 55lbft with ARP lube if a stretch gauge is not available. 

Rod dimensions are 136mm center to center length, 30mm wristpin, and 48mm big end. 

Weigh matched to +/- .5 gram per set total and end weights. Total weight per rod with bolts is ~703g, OEM BMW rod with bolts is ~670g.

FEA analysis image is for a 35K lb load applied to the connecting rod which corresponds to ~4075psi cylinder pressure.