^^^^^^^^^^^^^^^^^INT^^^^^^^-EXH
OPEN @.006"---------------338---------------110
CLOSE @ .006"-------------244--------------- 24
DURATION @ .006"---------266----------------274

OPEN @ .050"--------------5------------------136
CLOSE @ .050"-------------210---------------350
DURATION @ .050"---------205---------------214

LCA-----------------------121--------------243.5
LSA-------------------------------122.5

LOBE LIFT----------------.270"-------------.285"

This is from measurements and not a cam card.

1975 Ford F-250 camper special 390 4bbl c-6 trans

About ten years ago the engine was lightly rebuilt when the heads were pulled off to install hardened valve seats for unleaded fuel. Aside from stuff like piston rings, bearings, and gaskets, the only things changed were the camshaft and timing chain. Prior to the rebuild the engine ran strong. Afterward the engine just didn't quite have the same punch. Naturally I suspect the camshaft. After some research I have found that there were a couple different timing chain gears. One was the standard and the other was for emissions. So I'm wondering a bit about that too.

I have very little practical experience with what cam numbers mean in real life. I know that the numbers above are not delivering what I want. I figure there are folks here who can look at these numbers and give me some useful information.

From looking at those numbers it does seem like valve events are occurring a bit late.

Any thoughts?

Cook

 

NOT sure of the OE cam specs but you might try calling a couple places like JEG's or SUMMIT RACING toll-free line and asking. I've seen RV cams for less $$ than stock. There are a LOT of options avail. Might even be more info on-line. { 'Research time' awaits ] Some cams can be advanced (rotated) accordng to the gear-to-cam bolt "placement". << that last line may sound goofy / but some "cam-timing" is adjustable.