Pier/Beam foundation help

[Bigtex32]

Hello, I am new to this forum. I have tried searching everywhere for these answers, but not alot of luck.

Situation:
Currently my homesite has a doublewide trailer installed on concrete runners(28ft x 2 ft, that are 6.5ft apart, for 64ft). Between the concrete and steel beams are concrete blocks.

Build:
I am wanting to mimic this design for the Universal 2 story 20x34 design. The concrete runners are in perfect shape.

Concrete blocks I would imagine would work fine as the piers, since its worked fine for the mobile home?

Beam size is the thing that gets me the most. I have seen several postings with a girder size chart, but not sure I am reading it correctly. I was originally thinking 4x6 treated lumber to span over that 6.5ft distances between runners. But after looking at that chart, it would appear I need 3-2x10's for the beam? Does that sound correct?


Thanks for the help