OP - did you look up there OE cam part # using your engine serial # ? If not, do so, and maybe we can look up specs from there.

The Melling is a liitle less at .050 ( 201/208) but the same "advertised" (270/276) If the engine is together can you stick a degree wheel on it and see exactly what you have for sure ?

No specs - its all hidden -

HOWEVER i just found this from dennis moore on his store page: (hes up the road from me fwiw- and VERY knowledgeable )

Puts the crane cam I referenced just about on these specs-

"This is a VERY powerful camshaft!

fits

Chevy/Mercruiser V8 1987-PRESENT

305 350 5.0L 5.7L



Hydraulic Roller Camshaft

Replaces Mercruiser Part Number

431-811658



The original hydraulic roller lifters,

push rods, rocker arms and

valve springs can be reused.



This new hi performance camshaft has

220 degrees intake duration @ .050

224 degrees exhaust duration @ .050

.474 inches of intake lift

.474 inches of exhaust lift

111 degrees of Lobe Separation Angle

This replaces the stock marine camshaft:

197/207 intake/exhaust duration

.430/.450 intake/exhaust lift

109 degrees of Lobe Separation Angle

This Hi Performance replacement camshaft is a direct replacement for the stock camshaft and requires no additional modifications to the engine.

The stock carburetor jetting and ignition timing are maintained.
"

How would the reduced duration compare to the higher duration? Create more dcr / trap more cyl pressure perhaps? I would think the prime torque range on a 383 would be a little less critical due to the stroke already making these torquey-

After 10 post anyone can upload pictures.

If that is true then I need to find out why I cant

OP excuse the slight hijack.
1) Hit the "double mountain" box next to the smiley. 2) The upload screen appears. 3) Browse your device for an image or insert a URL where the file is hosted. In this sample it's from my device. 4) Hit the upload tab.
Screen grabs of the process in order below.

Dummy me I have been looking at the bottom where it says "you may not post attachments" Thank you !!!!!!!

Happy to help! Dummy my ass. You always have good sound advice and are knowledgeable any time you chime in.