GM/Merc Dimple Rods ??
 

I recieved a set of 8 Dimple Rods from a friend.... BUT, they had
3/8" ARP bolts in them not 7/16" as is normal for Merc stuff. Has anyone seen this before??? What gives? :eek: :confused:

ttt.... surely someone knows...... Dennis???????

THEY are not the good rod ! They are o.k. but not the better chevy rod :rolleyes: :rolleyes: :rolleyes:

.... I hate to say this Bobby, but.... the rods do have the GM dimple on them... otherwise I would agree with the "not good" rod..... how can a "bad type" rod have the GM dimple???? & still have the 3/8 bolts????:confused:

i believe that all of the high performance GM connecting rods have 7/16 bolts and the 3/8 came on all other big blocks the 3/8 rod is a good piece but not as good as the 7/16 the 7/16 were in all 454 mag motors and all 502 the 3/8 were in the lower hp motors. i believe the difference from rod to rod is that the 7/16 bolt rods are shot peened and cleaned up and drilled for 7/16 and the 3/8 rods are not.
later

Later is right The good rods are 7/16 bolt period ,Thats just part of what makes it better ,later is right on target ,dimples are really on small block rods ,big blocks are more determined by the bolt and shotpeen,and some rods girth :rolleyes: :rolleyes: :rolleyes:

That's what was confusing me.... the dimple. I know about the 7/16 bolts, 5/8" nut part but everyone always refers to the as "dimple" rods and here I have a set of "dimples" without the 7/16s' bolts! They are also polished beams so I cannot verify forged or cast. I will take a picture & post next week (they are at the lake shop).

Don't feel bad more than you have been confused with the dimple but that is really a small block term ,but the 7/16 big block rods after 92 do also have the demple but not all the time like the small block .
Just try and find some 7/16 rods if you have something thats going to need it as the rods you have with good like ARP wavelock bolts will work most of the time,,, as in boating we don't turn alot of rpm's which break rods most of the time ,good luck

I think those are early big block rods like from the 1960's. They are good rods but the weak link then is the bolts. How good are your machining skills to open them up?

Those are very good rods and they are from the late '60's-early '70's. Just use ARP 3/8" bolts and have them reconditioned and they will be fine under 7,000.
If you don't want them, pm me with a price.