rod weight question

i have 6 oliver rods that were said to be at a certain weight, in a box with everything marked.
i purchased 2 rods that should have matched these very closely. i was going to balance them and make the set whole.

the box said these were BBMX rods at 6.8 length. so about 275 and 600 for a 875 total. i ordered two BBMX8 rods and they weighed in this range when i received them.

then i measure the other six and to my surprise they are regular BB8 rods 250, 575, 825 weights. not sure what went on with the person selling these 6. they are matched and good rods, but not the version the box says. (they are 6.8 as they are suppose to be). i just foolishly used the numbers off the box instead of getting out the scale.

my question, can BBMX rods be lightened 25 grams on both ends or is is best to try and swap these around with oliver? i weighed out 25 grams of weld grade steel and it is alot of metal.
i bring a caliper if i am buying rods, i guess i will need to bring scales as well.

as an aside, i tried to figure out where the extra 50 grams were between the two types of rods. must just be a little extra everywhere because no dimension was significantly different between the two.

thank you for any insight

chris

Maybe call Oliver, and explain the situation, and see if you can swap the rods for the correct ones, and if not, ask them if it's safe to remove material from the heavier ones to match the lighter ones.
I bet it can be done, it may not look pretty, but once inside the motor, no one will ever see it!

that was the plan for monday. impatience and curiosity had me ask.
i am curious where the extra 50 grams was placed though. that is a fair amount of material and if you stack the rods you just dont see any obvious differences. put it this way, if side by side, you couldnt pick out the heavy one.

I think your asking a lot to grind 25 grams off a engineered racing rod, probably going to have to take the lesson learned and get 2 correct ones

Oliver rods are forged from AMS 6415 recipe chromoly—weight match ‘em and go.  

thank you for the reply.
i forgot i had a hurt oliver rod. i will experiment on that as well.
for reference, 25 grams is equal to 1"x1.5"x0.125" piece of steel. that has to be removed from the small end and the big end.

in the end i will probably just keep the 6 good basic oliver rods back and find two more used ones to go with it at some point.

i will also call oliver and see what it would take to get six more max rods to go with the two i have and just make both sets whole.

but i will see if can remove 25 grams from the small end tomorrow (being that is about 9 pct of the mass on the small end it should be interesting. )

if anyone has a few basic weight oliver rods ~(250, 575, 825) they would like to sell let me know, would likely be interested. need to be 6.800" the six i have are BBF but BBC would be fine as well. the weight are very close according to olivers web site.

thanks all

chris