well i was tired searching for rods under $$$$$$$$ so i decided to shim my M2 adapter instead of shimming the whole thing (HVX + bas plate) as recommended by redrock team... then i could move backward the rods
i decided to do it this afternoon ... it is done now ! everything works just fine ! As i had 18" long rods i couldn't use wide angles below 28 mm as i would have seen the rods in my image ...