Are the Intake Valley Pan Heat Shield the same for the 383/400/440? I know 440's valley pan is a little wider as are the valley pan hold downs, but is the heat shield used the same or is the 440 one wider as well?

The "B" motor (361, 383, 400) has one pan, and the "RB" motor (413, 426 W, 440 & that oddball RB383 back in the late 50s/early 60s) has one pan, they are not the same. That valley pan is also the intake gasket and its a one time use item. If its not replaced, they tend to suck oil up between the valley and the bottom of the intake ports.

I've referring to the heat shield portion that bolts on with the hold downs. I think they usually have some type of insulation between the heat shield and valley pan.

Think about that, I have never seen both of them beside each other but I would bet money they are not identical

Parts book shows different part numbers for the end rail reinforcements between the B and RB so the shield would have to be different also. Can't find a number for the shield itself.

The distance between the heads is different. The RBs intakes are 1" wider then the B motor intakes are..

i don't know where i got these measurements, but i was thinking 11" for the B, and 12" for the RB ?
i have a couple of each on the shelf, but i'm too lazy to go measure.
i'm thinking that may be from the top of the intake[s] ?

I was thinking 12" or 13", but it could be 11" or 12", its been 25+ years since I've even had my hands on any Mopar big block. The old memory isn't as good as it used to be.

my memory is being covered by cobwebs those dang spiders in my old noggin' are working hard to cover !

They are different. The bolt holes are spread apart more on the RB engines. You can reuse the gaskets if you use them with paper gaskets sandwiching them between the manifold and heads.

The heat shields are the same for the 383/440 that hold the insulation

Silencer Package Was Called
Part number - 1879 747
383 - 440



The holes are spaced 100 % the same on the hold down bars for 383 / 440

On a 440 the valley pan hold down bars are just longer on the ends , hence different part numbers for bars

Picture is 440 RB Hold Down Bars - Heat shields for 383/440

440 & 383 both have the same holes but the 440 is 8 1/4 long & the 383 is 7 1/4 long

Thanks.