Hey guys i just brought myself an XC GS panel van with all the GS options, it has the original 351 and 4 speed factory fitted with matching numbers and a 9" slippery. Also a brand new mandrel bent twin system.
But it has a slight problem. If i drive it like i stole it and give it a bit of s**t she runs sweet. but if i just putt around like grandma then as i'm coming back down through the gears and i get to 1st gear it keeps stalling and has trouble idling and sometimes it backfires through the carby.
Some people have said that the bushes in the dizzy are worn others say its the carby. What do you guys think?
Oh and it runs straigh LPG and hasn't been run on fuel in quite a while.

Hows your timing? Have u checked it?

is this when it runs on petrol or gas?
if it only does it on petrol then id be lookin at jets in the carby if its on both then look at electrical.

He stated straight LPG

pull out the dizzy and see how much movement is in the shaft
If it has a fair bit id get it rebuilt

What straight gas carby are you running?

Is it an Impco 425?

it might have a slight air leek