You could make the argument that accelerated conquests of regions outside of Italia would prompt accelerated technological advances but I am in favor of generally historical reforms, simply for the sake of continuity and balance--generally, that is. I could see a range of +/- 50 years or so as a good range. The true cause of the "reforms" were a lack of land-owning citizens able to be recruited into the Republic's army. This was a direct result of the Second Punic War.

Hannibal had destroyed many farms and those surviving faced competition from cheaper produce which was now available in the provinces. Many peasants did not have the skill or resources to switch to other forms of production, and whilst the level of competition was not sufficient in itself to make viable farms untenable, it did prevent the restoration of many of the
farms destroyed by Hannibal. Many veterans' farms had been bought out by the state and wealthy equites, developed into plantations. (latifunda).

This severely lessened the amount of land-owning citizens who would qualify for military service.

What if there was not an Invasion of Italy, and the citizen-farmer persisted into the 1st century BC?