"Ivan Vegvary" wrote:
-snip-
BTW, my existing plates (double 2x6) are in excellent shape. No bolts were
used so I would like to drill up into the plates and hang bolts before I
pour concrete. I also need to level out the house. It goes up and down
about 2 inches, which is why I am replacing the foundation in the first
place

I'd want to add another [treated] 2x6- but it is your choice. If
you're in a dry area that doesn't have termites, then it probably
isn't a big deal. I'd still at least treat the parts of the sill
that you'll [hopefully] never see again.

Here's how I did mine a couple years ago. This old house managed to
lose 25' of foundation [100 yr old dry stone] on one wall- and 20 feet
on the adjacent wall. The corner held, and we managed to replace
the walls without even cracking sheetrock upstairs.

Cribbed the crap out of it immediately.
Replaced sill & drilled holes for 'L' bolts.
Replaced cribbing with a solid steel post every 10'- Post gets buried
in wall- and has its own footing that goes below wall footing so the
final footing is an uninterrupted, reinforced unit.

Level house to its final elevation.
Insert L- bolts in holes.
Ran wall to within block height plus 1/2".
I used bond beam block for final course. [block with one side solid so
you can fill it with concrete] Using wedges to force it tight against
sill, I placed block- then used a 'pastry bag' to fill gap with
mortar. Removed wedges an hour or two later- and filled gaps left by
them.
Filled top of bond beam blocks.
Snugged up bolts next week.

I used 10 inch block & set the wall deep enough to allow for 2"
insulation and a parge coat on outside- so I had room to get a 3lb
coffee can up there to fill the blocks with concrete.

Good luck-- this isn't the most fun I ever had, but the end result was
gratifying.

Jim