427 Rods

[Nicholas M.]

Did GM use the dimple rods in the 390/400 HP 427 Corvette's?

[Mike M.]

Re: 427 Rods

don't think so, but i've always used them in my 2 bolt mark IV engines.can't hurt and may save a bbc from grenading at rpm.mike

[Clem Z.]

Re: 427 Rods

there are much better aftermarket rods out there for less $$$$. used rods need to be resized,maged,checked for straightness,new bolts and they are not all the same length.

[Duke W.]

Re: 427 Rods

What Clem said. Whether a small or big block a new set of rods from low cost vendors like Eagle will likely cost less than what it costs to inspect and refurbish OE rods, which are still weaker even if they pass all the inspections like Magaflux and are properly resized with new higher strength bolts.

Usually the least expensive aftermarket rods are up to the task to at least 7000 revs, and you want to make sure they are not significantly heavier than OE rods or balancing the bottom end could be problematic.

Duke

[Joe L.]

Re: 427 Rods

Did GM use the dimple rods in the 390/400 HP 427 Corvette's?

Nicholas------


It depends what you mean by "dimple". If you mean a small "bump" near the small end in the middle of the beam, then the answer is no. All rods with the "bump" were 7/16" rod bolt type and none of these were ever used on L-36 or L-68. In fact, none were used on L-78, L-72, L-71, or 67-68 L-88, either. All these applications used rods with 3/8" rod bolts.

There were actually 3 different rod designs with the "bumps" (and 7/16" rod bolts).

The first was the 1969 L-88 and ZL-1 rod. Originally GM #3942407 and later GM #3959187 and 3969804, this was the strongest of all factory big block rods. It was designed for floating pins and used special boron steel rod bolts. These rods were 100% magnaflux inspected and shot-peened and are forged of 4340 steel.

The second was the 1970-71 LS-6 rod. It was also destined for the still-born LS-7 (which was available as a crate engine). Originally, this was GM #3963552 and later GM #14096151. These rods use a smaller beam cross-section, but its improved design is supposed to result in a rod nearly as strong as the above. This rod uses a pressed pin and knurled shank rod bolts. These rods were also 100% magnaflux inspected and shot-peened. These rods are manufactured from 4340 steel.

The third was GM #10198922. This rod is an improved version of the above LS-6 rod and also replaced it for SERVICE. It was also used in PRODUCTION on all Gen V and Gen VI big blocks. It is otherwise similar in appearance and features to the 14096151. It's still available from GM for about 120 bucks, each, GM list. Several years ago GM had this rod available as a set of 8 for a super sale price of 350 bucks from discount GM dealers. I made sure I "stocked up" then. The set is no longer available.