Mopar Muscle Association UK

As the title says, my 273 runs sweet as from idle to cruise, but if I try to push past 3,000rpm it starts to fall right off. No backfires or drama, the motor just seems to run out of energy.
Culprits?
Worn valve springs
Ignition issues ( still on points)
Just wondering

Get a reading off the timing first. It’s an easy check before pulling things apart.
You know the numbers ( somewhere in the teens for initial likely, 34ish all in) - at what point does it hit peak timing? Does it move past 3000 ?

Thanks Morgan, not had time to check yet, but I usually advance my dissy as far as the motor wants to tolerate.
I believe that the distributor is a dual point, but only running one set of points. One of the yank forums noted that this can lead to reduced spark efficiency at higher rpm.
Think I’ll check that the advance mechanism is functioning correctly and probably upgrade to electronic ignition as I believe the dizzy is likely still original.

Before looking at anything else make sure you are actually getting full throttle, someone in the car with their foot to the floor and see if you can open the carb further, slip off the kick down rod and make sure that's not limiting it either.

I did mate, first thing this morning. It’s an odd one, just seems to run out of breath. Given that 273s are meant to rev to make any power, it’s a bit odd. Motor sounds and runs sweet otherwise, but stick it in first gear and hammer it and nah, not so much

When things just go flat it’s not usually ignition related. Could be fuel starvation or something like the flap in the exhaust manifold not fully open.

Ok, I’ll check. Never thought about the the exhaust side

Cheer Blue, simple fix. I assumed that being a stock motor everything was set correctly. A quick check of the kickdown linkage showed I was getting 1/2” less full throttle. Parts were seized up so after getting medieval with it I reset the linkage and now the car revs as much as I want to give it.
Which is nice

Result
Nice when it is a quick fix. These boys have seen it all...