I have a Hays 11-340 flywheel which is neutral balanced (I believe), but my 440 is a 1970 HP externally balanced. Can the flywheel be weighted for the motor and if so, how? Or is there another option I should be looking at?

I also have a '69 stock 440 flywheel - but I think it is neutral balanced as well. Only the six pack 440's were externally balanced in 69, right?

Man, this 4 speed conversion is frying my brain already. But nothing like side-stepping the clutch and power shifting. It's been too long.

It's my belief that your 1970 crank is steel and does not need external balancing unless it's from the 6 pack engine.

Also, does the end of the crank have the pilot hole to receive the 4 speed?

1970-1972 HP 440's were externally balanced. They all had 6 pack rods, even the 4 barrel versions. If I am not mistaken, the '69 1/2 6 pack motors were internally balanced b/c they had LY rods. Doesn't matter if the crank is steel or cast, if it has 6 pack rods then it's externally balanced.

Just went through this on my dad's road runner. I had the rotating assembly internally balanced, it was a 1971 HP 440 w/ 6 pack rods (external balanced motor). Makes changing flywheels later on down the road much easier. CHIP

Thanks for the responses.

So am I screwed?

Can only the original flywheel for the motor be used (which I don't have because my motor had an auto trans originally) unless I pull the rotating assembly and get it all rebalanced?

You might be screwed eventually, but not yet.

Old trick is to install the neutral flywheel, then weld the appropriate weight onto teh pressureplate housing. I've never had to do it, but I've heard of doing it. You'll have to research that one further.

The old-school reports were that all steel cranks were drilled for a manual trans, but I've heard of enough exceptions over the years that I would verify mine before trying to throw a trans in the car. If yours isn't drilled, Napa has a 'conversion' bearing that fits into the outer section of the crank hub. You'll have to research that one too.

The neutral balanced flywheel can be modified for the external balance needed for the heavy rods, this amounts to drilling some holes opposite the side that needs the weight. The top diagram in the pic below shows how:

As far as I know, the only way to balance the flywheel for this application is to have the rotating assembly out of the motor.

Like Fury Fan said, I have heard of welding weights to the pressure plate. That would be a pain b/c when it comes time for a new clutch and pressure plate, you'll be doing it over again.

In the long run I think you'll be better off internally balancing the motor. I know that's a pain for you with your motor running good and all.

There is a roller pilot bearing for cranks that never had a pilot bushing installed. That's what I used on my dad's car. I had a friend get me one through Mopar Performance. Sorry, I dont remember the part number for it.

With all the '70 and up 440 HP motors that had 4 speeds behind them, you'd think an externally balanced flywheel would be easy to come by. CHIP


edit...I think John Kunkel just saved the day, lol. Hope that works for ya!!

Thank you John!

I assume that this procedure is for the 11" neutral balance flywheel?

Thanks again.

Passon and brewers will sell you a flywheel for an external balance 440. Also there's a weight kit/template out there for adding weights to a neutral balance torq converter. Someone posted once that they were able to add those weights to their flywheel successfully.

OK

New solution. 69 internally balanced motor. Thanks for all the help and info. If I knew it was this hard to use the 70 motor, I think I would have gone this route from the beginning. Sorry for being a pita. But thank you for the education!

Thanks for the clarification. I think both my cars are going 4 speed now

Quote:

---

Quote:

---

Thank you John!

I assume that this procedure is for the 11" neutral balance flywheel?

Thanks again.

---

Yes that procedure will work for both the 130 tooth or 143 tooth wheel .

---

I need to post on this to save it.

So this will work to put my 70 internall bal flywheel on a 74 externall motor ?