Probably pretty little, considering that the embargo was leaky as a sieve on both sides. It might give a slight advantage to the Israelis, who will have Allied WWII surplus to go along with their Czechoslovak-made German knockoffs (which the British sold to the Arabs pretty shamelessly)
In practice both France and UK obey embargo would great deal effect as me. Egypt ask UK for combat aircraft and combat ground vehicle ammummia and UK refuse. Israel had dealt with more air raids UK said yes to Egypt demands. UK also refuse to give Jordan more weapons asking for in 1947. So surly little more bloody Israeli if UN put armbargo on