Choosing a Harmonic balancer 440 RB

[hpg4815]

I'm trying to purchase a new Harmonic Balancer for my 440 RB engine that I just had rebuilt.

The situation is, my father bought this built motor from a guy, and put it in his car and drove it around for a while. I recall him stating it was a 440 magnum, but I do not recall seeing any "HP" markings on the block. I will recheck that. Anyway, I have the harmonic balancer that was on the engine when it was running, and I am looking to replace it. There are not any identifying mark on it. Having said that, the steel forged crank shaft installed, is internally balanced, and therefore I do not need to get a externally balanced fly wheel or harmonic balancer. What I am wondering is, is there a difference between a RB 440 and a 440 magnum in relation to harmonic balancers? I have 906 heads installed.

I'm wondering, based on other posts, if the HP identifiers on the block makes it a magnum block? I have a 440 RB, and I don't recall the HP mentioned on it.

I'm trying to determine if the block is a "6 pack" related engine, or a "440  magnum", or just a "RB block". and would each of these blocks accept a different harmonic balancer size and or weight.

In reading i have identified that the "6 pack" does have a differently weighted harmoni balancer. Now I am just wondering if there is one specific to the magnum? The one i have (old one), is around 7.25 in dia, and i believe it is around 8 or 9lbs


Any help on this would be greatly appreciated.

[justcruisin]

From the factory the 70/71 Hp block has a weighted balancer, - 6 pack or magnum run the same balancer. If it is internally balanced steel crank then take your pic on neutral balancers.  If it is an HP block it will be stamped HP 440 or HP2 440 on the ID pad. Doesn't count for much though, only to a numbers car. However, anything could have been changed over the last 50 odd years.

[hpg4815]

Hi again and thanks for your speedy response....

You say 70/71.... My block has 8-14-1969 cast at 9pm with stamp # 2536430-10. Since the cast date says 8-14-1969, can I safely assume this is not a HP block? Where exactly would I see this HP stamping? With the date and number I mentioned above?

Yes. The machine shop confirmed it is a internally balanced steel crank and I had it sent off to get re-balanced.

When shopping for a neutral balancer i've found 2 in the same diameter as the one which the car ran with that go to to a 1969 440 RB engne. I cannot say it was the original one, but I was using that one as a reference. There are 2 different weight replacement options for the 7.25 diameter I have. One was 7.4lbs and the other is 9.4lbs. Mine weighs 8lbs.

Any insight on what weight balancer I should go with? I don't want to have to pull this thing off if its wrong. Based on my reading, it sounds like the difference b/n a regular RB 440 and a magnum or six pack 440 it the rods are heavier. If the block does not have HP stamped on it, does that mean those heavier rods would not fit in a non-HP block? If so, then I just need to confirm that its not a HP block and I am good, correct?

Thanks again

[BLK 68 R/T]

http://www.440source.com/dampers.htm

[justcruisin]

The factory made HP engines that were internally balanced prior to using the heavy rod which required the engine to be externally balanced. If you have an HP block it will have the markings on the ID pad which is at the top drivers side of the block forward of the valley plate. I would think some 70 heavy rod engines were cast in 69 but if your engine guy says it is internally balanced it probably has the LY rods or aftermarket. As to which balancer to use, it depends on your application but an SFI approved unit is a good start, get some advice from your engine guy.

[hpg4815]

Thanks for all your help! I ended up buying a damper from 440 source and it appears to have gone on right. Also I checked for the HP stamping on that tab and there wasn't any related to "HP".