Boot RHEL6.7 with 7.4 initrd and kernel

Hi,

I have a customized RHEL6.7 server, it has several LVM2 partitions, the root volume is LVM2 based and is located on: stats/rootvol

im editing the current GRUB (0.97 which part of RHEL67) to look like that (some params are for debugging, i know....):

title Upgrade Phase (RHEL 7.x)
        root (hd0,0)
        kernel /Upgrade/isolinux/vmlinuz ks=hd:sda1:/Upgrade/ks-upgrade.ks ramdisk_size=8192 root=/dev/mapper/stats-rootvol rd.lvm.lv=stats/rootvol rd.lvm.vg=stats rd.auto=1 rd.shell rd.debug log_buf_len=1M console=ttyS0
        initrd /Upgrade/isolinux/initrd.img

initrd.img is the one that comes from official RHEL7.4 so as the vmlinuz (kernel). both are available under /Upgrade/isolinux/.
The issue im experiencing is that dracut complains about not finding the root partition: /dev/mapper/stats-rootvol

after dracut times out, i see only /dev/mapper/control, but when i run (under dracut shell) the following:
lvm vgchange -ay

i do see all my LVMs under /dev/mapper/*

what am i doing wrong here?

Thanks,