what year is my motor also no power under a load

I have a Chrysler
Model# 857HD
Serial# 4324

it idel's a little ruff an dies when i ram it wide open, never gets past 10 miles an hour

'72
http://www.maxrules.com/ChryslerModels/50_85.html

What kind of compression readings are you getting? Spark on all cylinders good? Primer bulb "stiff" when running? New fuel mixed properly? Just some places to start.

Like daves69 says start with a compression/spark test.

More info please.Does it rev up or run low rpm's? What's max rpm's?Reving up and no speed could be a bad prop.

Low idle will cause it to stall on acceleration.What's the idle rpm's?Does it stall when put in gear?
Any water in the gas?
Start by changing the fuel pump diaphram.Then clean the carb and reset the air screw.In till it just bottoms(gently) out, and out 1 and 1/8th turn out.
Idle should be about 750-800 rpm's.You NEED a tach or nothing your gonna do is gonna be right.
You can guess but it needs to be right.Do this and get back.J