Here's a video...

It always acts like this in the cold, but occasionally it pops and pours out white smoke in the higher rpms when i get on it...

when it's cold it sounds like a petrol engine rev-limited around 3000rpm... bounces 3000-3100rpms...

 

Thats a great way to blow a headgasket. Thats also about the worst move you could make with a cold truck.
First of all, Plug it up!
Adjust your timing and run a good additive. It's an old manual pump truck, If it runs fine warm I would worry about it, but a cold rev like that is HARD on one!

 

I don't run my truck like this in the cold... not usually... this was just to demonstrate how it acts when it's cold...

it occasionally does it when warm as well... in the over 2600-2800rpm range...

And i can't plug it up because the block heater is 110V and in Iceland we have 220V...

 

Ohhhhhhh....Iceland...Just caught that Lol.
Well then, I would say timing, and check the governor springs. Have you installed a GSK yet?

I'm sure they probably have some block heaters that will work for your use!

 

no i havent installed a GSK, i was looking at running 4k GSK with the 60lb springs... but i bet i will be going for 3k GSK.... i can rev it to 3400rpm when idling though ??? maybe someone installed a GSK in it before i got it :P

 

It will continue to rev, but not continue to fuel. When pulling it will stop fueling well before 3400 RPM. That pop and crack is pretty common in a cold truck. Timing can help with it quite a bit, and some say it's an injector issue. I would start by checking the timing and ALWAYS let it reach atleast 150 before reving like that and 190F before boosting it hard!