69 383 Ply Roadrunner Top Speed?

One thing you forget. A 440 has a larger bore than a 383, meaning less
iron in the block (marginal, but there is a difference) It also has a
longer stroke 0 meaning a difference in the crankshaft - likely
heavier on the 440 - whick may more than make up for the difference.
Then again, I think the 440 rods are shorter than the 383 rods - which
would make them lighter.

At any rate, there is more difference between a 383 and a 440 than
just an aluminum manifold and water pump, and more diffewrence between
a Runner and a GTX than just the engine.

Actual factory shipping weights for440 gtx, 383 runner, 318 sport
satellite, and 318 satelite (all hardtop coupe bodies) are 3465,
3450,3156, and 3151 lbs respectively.

The GTX had heavier battery, heavier suspension, heavier duty
tansmission, and different interior (not sure if the seats were
heavier or lighter, but generally vinyl is heavier than cloth)

 

my 73 charger with a hipo 400 did a easy 145 but i never had the balls to try
to bend the needle past the 160 speedo so i'm dam sure that r.runner would do
it

 

Realistically, probably around 120 mph in stock trim, but not for
long- the cars weren't designed for continuous high-speed operation
and something would fail rather quickly, likely with fatal results.
********
OK I'm putting my 2 cents in here:
First, I'm inclined to believe the "near 140" estimate. I had a '71 340 RR
with the same rear, but straight shift & it would do the 140 with the air
grabber up (only 135 with it down). The RR 340 was the "Cyote Duster"
engine with 340ci, 340 HP, & 340 ft.lbs.torque - not sure what the specs
were on the 383.
Also, I could run my bird as long as I wanted to at WOT, & never had
*anything* fail. The *only* problem I ever had with the car was a broken
alt. bracket.
I will also add that the GTX *was* heaver than the RR: it had a lot of
extra "luxuries" as well as sound deadner, etc. The RR was a striped down
machine.
~ Paul
aka "Tha Driver"

Giggle Cream - it makes dessert *funny*!