1964-1990 Strengthening/Machining



If you have an engine apart, and have a 4" grinder and a die grinder, it's recommended to polish the rods' side beams. Most importantly, it removes the stress risers (which weaken the rods by providing a start for a crack which leads to failure). So this in effect strengthens the rods. Less important: it allows the rod to shed oil a bit faster to reduce reciprocating weight during engine operation.

Just grind fairly smooth with the 4" grinder, then smooth over with a flappy-sander in the 4" grinder, then a little 80 grit flap wheel in the die grinder will make them a joy to touch and behold. Then run over them with a 240 grit flappy wheel will polish them to shiny. Easy, though time-consuming - about 2 hours to do all 8.

Beef up the block by installing either a main stud kit or a main stud and strap kit. For longevity on the connecting rods, have them stress relieved and install ARP rod bolts.

I installed a main stud kit in my 455, and the only problem I had was with the windage tray. The trick with the connecting rods is to install ARP rod bolts, and have the rods resized. Then take them to a machine shop and have a .500 WIDE slot in the top and bottom of the main bearing journal machined .010-.012" DEEP. Then I would have your rotating assembly balanced. A good machinist will balance the harmonic balancer, connecting rods, pistons, crankshaft, flywheel/flexplate and pressure plate.

[ Thanks to Chris Witt, [email protected], Steve for this information ]