1974 440. Cast crank. 2 harmonic balancers were included with the engine but neither was installed. Both are cast, both in great shape. The lower pulley i have is a 4 row pulley and I have AC, power brakes, power steering. Both have the same diameter. The 6 pulley bolts line up perfectly with the thinner (7/8") one. They are off a bit on the thicker one (1 5/8"), but will fit. Does it matter which one I use?

BELL? are you talking crank pulley on damper or bell housing on a transmission?

yes it matters on external cast crank 440

early dampers have 1 bolt offset and later one are symmetrical on the pulley bolts.

my 77-78 cast crank damper says cast crank 440 only and is a bullet nose style.

I am upgrading it to the INTERNAL/EXTERNAL balancer that has a weight to bolt to it for external balance. timing marks to 60* btdc

summit = PFS-80013

now would be a good time to upgrade the damper rather than chance the wrong/used one of unknown origins.

my 0.02$

I too am confuse by the "bell housing" term.
Do you maybe mean timing chain cover, or maybe the lower pulley?
As scratching said;
Harmonic balancers, go on the front of the crank.
The bell housing refers to the transmission in the back of the motor.
yes it matters witch one you use.

Sorry I meant lower pulley on the front of the harmonic balancer

7/8" seems pretty thin for a cast crank balancer, that sounds like a steel crank "6 pack" balancer (forged crank with heavy rods). The '77 440 in my coronet is thick like the 1 5/8" one you mentioned. Do you have pics? Also is this a rebuild, or just throwing an engine back together with stock parts?

look on 440source and read the info on dampers. that will let you ID what/yr dampers you have.

with a 74 you may have the correct one on hand.

what is the 440 engine out of?

MH 440s got steel cranks/6-pac crank/heavy rods/cast crank/LY rods

either internal or external balance depending on which crank rod combo

could you post up some more pics as you go? I am interested and thinking a missing damper outer ring also.

seems I have seen a ferd engine with a hub and pulley only and no damper but thought Humm..must be a ferd thing.

Update, after checking the 440source site. I think the thinner one is a 71 and earlier "6pack dampener" because of the off set pulley bolt pattern. I can't use it as it's not cast.
The thicker one that says cast crank has an symmetrical bolt pattern. Now I guess I need another symmetrical pulley because the one i have is not symmetrical. or can I just open up one of the holes slightly on the pulley to make it symmetrical?

You can oblong one hole did it a few times. I might have an extra, I have to take a look. Do you want to sell the 6 pack dampner? Im interested.