I've actually owned my pocket hole jig for quite some time, but it has had such little use a long time ago that I'm virtually starting again. I'm in Australia so our measurements and lumber sizes are slightly different to the US.
I'm going to be using a lot of 70mm x 45mm (actual finished size) timber over the next few weeks and I was wondering what the best Kreg Pocket Hole Jig settings would be.
A nearest-decimal-place conversion of 70mm x 45mm is 2.75" x 1.75".
Some of the pocket holes will be on the narrow 45mm side and some on the wider 70mm side.
Standard Kreg Jigs® are designed for use with material from 1/2" to 1 1/2" thick (12-38mm). On the 1 1/2" setting, you will want to use 2 1/2" Kreg Screws. This will give you the strongest hold possible. We also offer a Heavy-Duty Kreg Jig® — optimized for use with materials 1 1/2" thick and thicker. Feel free to get in touch with Technical Support at 800-447-8638 or email@example.com with any further questions. They are very knowledgeable and will be more than happy to offer you their best advice. Thanks!
I highly recommend the Kreg Jig HD and its associated larger Kreg Jig HD Screws.
I've used them to build some frames using 1-1/2" thick lumber (most of it 1-1/2" x 5-1/4" -- what we in the U.S. call a 2x6) and it performs very very well and strong, STRONG. I especially like using the bigger HD screws - knowing that they will be that much stronger than the standard Kreg Screws (which in themselves are excellent screws). Since most of the 1-1/2" lumber is softwood (fir, pine, ...) I also like the HD screw's wider coarser threads which I assume at even more strength (just makes sense to me).
Depth-wise you will be safe from having the screw points come out the back side of the non-pocket hole timbers.
Given than your timber dimensions are larger than the 1-1/2" (38 mm) lumber that the Kreg Jig HD is designed for, the screws will enter the non-pocket hole material off-center - closer to the pocket hole side. This shouldn't cause any problems - the joint will still be VERY strong, but if it doesn't harm the look of your project you may want to alternate putting the pocket holes on opposite sides of the joint line to even out the joint stength side-to-side -- if that makes sense.