hi just got a second hand a frame i was told the chain go's to the outside of the pin and not the inside of the pin (see pics ) i was thinking he may have got it wrong he did not know much about it and had only used it the 1 time (have always been told it fits to the insidelike the pic)

Can't see it making much difference.

Personally I would think about changing the chains to straps.

Surely straps can wear and strap.... chains would last much longer?

Thats a good looking home made A frame, the pin looks a bit too tall making it a bit close to the floor. Makes no difference where the chains go.

Keep the chain. As has been said, a strap can wear particularly if your lower wishbone or suspension arm are sharp edged. I also agree that the upright is very long and would lead to it riding up and down in use. Is your chain tensioned with a ratchet strap? It is not critical which side the chain goes. It is all dependent on the style and shape of your lower suspension arm. When I fitted mine I would tension the chain on both sides then re-check it when you put some tension on the A frame by towing it a bit just to make sure everything is nice and tight. Of course, and you probably realise this anyway, do not have your steering lock on and you cannot reverse the unit. BTW it is actually illegal to tow anything that is not actually broken down and only for recovery and there is a speed limit which I think is 30mph but someone will probably know exactly.

Chains are stronger. The only advantage of straps is to prevent damage to the modern alloy suspension arms.
It makes no difference what side the straps/chains go as long as they are tight. Always pull over after a couple
of miles to tighten things up.