Difference between '68 440 and '70 440

[Chrome58]

Hi everyone,

What are the differences between a '68 440 and a '70 440 ?
Thanks.

 

[FURYGT]

They both had the same HP ratings and used the same heads. Different C Body left side exhaust manifolds between the 2 years. Is there something specific that you want to know?

 

[Davea Lux]

The block is going to be the same. The '70 has a lower compression ratio and more emission controls. Carbs tended to be leaner for '70 and the timing specs were less aggressive. The '70 engine ran different LH exhaust manifolds on the HP variants. The '70 engine also has the vehicle Vin number stamped on the block and this is part of the numbers matching criteria, as well as the casting date ('68 will have a casting date two years older). All six pack/6BBL engines and some others (mostly police cruisers) had the heavier six pack rods. Both engines shared the same 906 heads.

Dave

 

[Wollfen]

Also the valve covers will be different as the ignition wires were routed differently.

 

[moper]

The date on the side, and the valve covers mostly.

 

[fury fan]

The HP engines in 1970 (6-pack, Magnum, TNT) have the heavier rods and external balancing that Davea mentioned, and it is a different balance weight than other ext-bal 440s.

 

[CBODY67]

Basically the same engine "long block" for the 375 horse motors. Detail differences in carb/distributor calibrations for emission compliance. Some differences in the pcv system, in some cases, but more in common than not.

The rated compression ratio was slightly lower, but not enough to make any real difference in power or performance. The larger decrease came with the '71 models. But still plenty high enough to require "premium" fuel. Then the larger decrease in '72.

Not aware of any significant changes in the block castings, other than the casting dates? Or anything that would affect ultimate power production and reliability? OR anything different on the 375 horse motors than the 350 horse motors?

IF you are trying to chose the better one of the two, that might be a crapshoot. For rebuilding, you'll probably end up with a .030" overbore to get the bores cleaned up and all "fresh metal" to finish hone. Replacement pistons will not be the exact same weight as the stock pistons, so a balance job would need to probably happen. So, many "items of value" would be the same, to me. A 440 block is a "440 block", regardless of which one you start with . . . UNLESS you're chasing a particular date code for a restoration project.

If there might be a "HP" stamping somewhere, I believe that would reference what was IN the block rather than it being a better block per se. The Motor Home "hour glass" water passage block is similar, just that the "hour glass" hole in the deck surface is more there for ID than greater water flow. Once the head gasket is installed, the hole becomes a "normal" hole due to the restriction hole in the head gasket itself. IF the motor home 440s used a head gasket with a larger restriction hole, then that hour glass shape might really be better.

You might chose the one with the less miles, but both will probably end up taking the same things to rebuild it. So looking for cracks and such is important!

Just some thoughts,
CBODY67

 

[commando1]

Everybody through?

What are the differences between a '68 440 and a '70 440 ?

Basically identical .

 

[Trace 300 Hurst]

Wait....different paint?

 

[73satwagon]

intake different casting, HP engines had windage tray, different cam, valve spring dampers different curve in distributor,carb

 

[detmatt]

Everything that bolts to the ‘68 engine also bolts to the ‘70 and the opposite is also true.

 

[63Fun]

The block is going to be the same. The '70 has a lower compression ratio and more emission controls. Carbs tended to be leaner for '70 and the timing specs were less aggressive. The '70 engine ran different LH exhaust manifolds on the HP variants. The '70 engine also has the vehicle Vin number stamped on the block and this is part of the numbers matching criteria, as well as the casting date ('68 will have a casting date two years older). All six pack/6BBL engines and some others (mostly police cruisers) had the heavier six pack rods. Both engines shared the same 906 heads.

Dave

The casting date doesn't have to be 2 years older than the model year of the car. Typically, it's a few weeks to a couple of months from that I've found.

 

[detmatt]

The casting date doesn't have to be 2 years older than the model year of the car. Typically, it's a few weeks to a couple of months from that I've found.

I think he’s saying 2 years older than the ‘70 and both my ‘68s have the vin stamped on them just in a different location.

 

[Chrome58]

Thanks everyone for your input.
You've been very helpful.

 

[Clover]

‘70 is generally more valuable on the open market, if it’s an HP.

 

[Chrome58]

Actually, I was looking to buy a '70 Plymouth that had a '68 440 engine in it.
Long story short : I wont't buy it.

But thanks again to everyone.

 

[commando1]

Actually, I was looking to buy a '70 Plymouth that had a '68 440 engine in it.
Long story short : I wont't buy it.

But thanks again to everyone.

Looking at your sig;
What is a "Dual Fury V800 engine"?

 

[Davea Lux]

The casting date doesn't have to be 2 years older than the model year of the car. Typically, it's a few weeks to a couple of months from that I've found.

Casting number for the '68 block is going to be about two years earlier than the '70 block difference of two years between when the '68 engine was produced and the '70 engine was produced for clarification. The date of the engine should always be prior to the production date of the car. On high volume production engines like the 318, the time span will sometimes be as little as two weeks. On lower volume engines, like the 440, the time span will sometimes be as much as two months or more.

Dave

 

[Snotty]

Two years, that's the difference.

 

[Chrome58]

Looking at your sig;
What is a "Dual Fury V800 engine"?

That was the marketing name given to the optional dual quad 318 on 1958 Plymouth.