Neither will affect Senate representation.
The first drastically lowers the tax burden on the south, but weakens their hold in the House. It also makes Southern states less important for the Electoral College. The North dominates much earlier. We can imagine several anti-slavery measures pass. This may not mean an earlier civil war, because the South wasn't as radical earlier on, and the North is less incensed at Southern obstructionism. It may quickly become apparent that the expansion of slavery won't be allowed, and Southerners accept that. Ironically, this may mean slavery lasts longer ITTL until some form of compensated emancipation is passed in the last half of the 19th century. Also, the lost revenue needs to be made up somehow, likely by a higher tariff which the South can't stop.
The second increases the taxes the Southern states need to pay, but they have even more representation. They stop and block all anti-slavery attempts. Slavery might expand more in a series of compromises to gett the necessary votes. Northern resentment increases, but it takes a Republican a lot longer to win the White House. Civil War happens later, but with the North even more of an industrial power. Without the unique circumstances of OTL John Buchanan and 1860, it could very well end sooner.