Weak/ soft springs are for when you have low vacuum produced from your engine. So it will be on the idle part of your metering rods.
What is your vacuum @ idle.
If you have stiff springs, as soon as you get low vacuum signal, your metering rods pull out of the main jet quickly causing it to get rich quickly.
When you are floored, you should have no vacuum,causing your metering rods to pull out of your main jet.
When you take the metering rod cover off,, does the little piston attached to the metering rod touch the cover?, Does it pop up out of the hole?
Now, if you take the metering rod cover off & you see the piston down in the hole,, then the spring is probably cut. Should replace them (springs).
Your hesitation on the top end??? Explain the what is happening.
I still think the problem really is the intake manifold is too big ,causing the carb not to get a strong signal.
I have both intake manifolds, been there done that.
An Offy intake will help trmendously.
That being said,,
switching to three side draught Webers, that my friend is going to be a day & night time difference. But reguires a lot of jetting & tunning.
