JAMES LOWE

Hi, posted a few days ago. Will going from a 286, 560/560 lift 230/230 @ 50 to a 292, 560/565 lift 243/251 @50 affect brake vacuum. When the 286 was in brakes still worked fine. The peddle is not hard to push it feels the same just dont wanna stop at low speeds. I believe i might have to bleed all way around i have to double pump brakes so might be air in line from putting rearend back in, just bled back when first put rearend in & not front. Any suggestions on this gladly appreciate it!