yep both the f and g series are bulletproof. Theres an ma70 in sydney (i think)owned by a fella called seb whos running a g series and is pulling 532 RWKW, or 712 RWHP. And it and the r154 hold up nicely.
Im keeping the f313 behind my 302 with confidence, but i may have to change to a taller ratio than 3.9 Also keeping my w58.