"Hemi" style rods for small block?

Is anyone familiar with P3614514 small block rods? Found a couple references online and an may have located some. The literature say that they are heavier than a regular rod and he weighed one at 2 lbs, 0.5oz which converts to 762 grams (Edit..That conversion is wrong, would be ~922Gr) . but the boxes have numbers on each end that look like weights and when added come up different. 182.1 + 432.4 = 614.5. I thought a stock 340 rod was more like 750g? Not sure what to make of that.
I'd imagine these should be as good as a modern Scat or Eagle I-beam rod. I'm putting my '71 340 back together with the stock dia OEM high compression pistons and forged crank, so I don't want to have to make a big balance correction.

These will be heavier than OEM rods. You'll likely need Mallory metal for balance and the extra weight will hinder rev-a-bilty. Lighter rods are plenty strong, like Scat I-beam and H-beam rods. Not sure if you'll have any clearance issues.

Locomotion said:

These will be heavier than OEM rods. You'll likely need Mallory metal for balance and the extra weight will hinder rev-a-bilty. Lighter rods are plenty strong, like Scat I-beam and H-beam rods. Not sure if you'll have any clearance issues.

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The weight is what's confusing me. I didn't do the conversion on the scale reading correctly 1lb = 453.6 gr. and he shows just over 2lbs which would be 907gr, which seems way too heavy. The weights on the boxes may be from other parts and the packaging re-sued. I'll have to weigh one of my stock rods tonight. I like the idea of the lighter rods but these are new and would be strong and not need a rebuild or bolts. Just comes down to what I can get them for.

The weights on the boxes are a little on the higher end of "advertised" numbers shown for Scat I-beam and Eagle SIR rods. Summit shows Eagle H-beam rods at around 695 grams. OEM rods are heavier and it wouldn't surprise me if the rods you're showing are actually around 2 lbs. I had a set many years ago, They are "bulky" and have heard the term "Hemi-footprint" associated with them.

I'm sure they are stronger than Scat or Eagle I-beams. But they are very likely for sale because they simply weigh too much to be practical for 99% of applications. As mentioned, Mallory metal and possibly 340/360 cast crank balancer/flexplate will be needed with them. That may negate the cost difference between those rods and an aftermarket alternative. (It's cheaper to take weight out of a crank using lighter rods.)

Just my opinion, but with OEM pistons, OEM rods or H-beams would be plenty. Scat I-beams would also work for milder applications. It's just that the crank counterweights would require a good bit of lightening and the OEM pistons are on the heavy side.

What the application for this engine? Street, street/strip, race?

Sounds like these may not be for me then if they’re that heavy. The car will see a lot of Street and road course and then occasionally on the dragstrip. Once on the road I plan to drive the **** out of it. I’ve got a second block build a stroker out of it with some aluminum heads when I get the money saved up but the 340 that came in it has 2.02 J heads and ran pretty good but the rod bearings were toast. Going to tweak it and put as big a cam as I can stand and play with different cam, intake, and carb combos.

Those are good for assaulting someone...

Use in an engine today, not so much anymore with the other better lighter rods available.

Those rods aren’t near as good as what you can buy today. No serious connecting rod is built with that architecture. And no serious connecting rod is built with a bolt and nut. They use cap screws for a reason. I also don’t think those rods are 4340 either. IIRC they are still 1018 or something.

I wonder how many used 273/318 rods back in the day to lighten things up. Plenty strong.

That happened more than most people think. I used to buy every 273 crank I could find. Several were given to me. Then I’d turn .100 off the OD and use a couple of sticks of Mallory in there to balance it. Vroooom vrooom. It makes a difference at racing RPM.

I would use new H or I beam rods, Scat Eagle etc, that use the cap bolt for any serious 'work'. Cutting the factory rod bolt head clearance seriously weakens the rod in an already critical area.