What to do.

Des,
It was good to catch up with you on the weekend.....
I'll stick with my recommendation to get rid of the Grand Treks and get a set of "proper" tyres for your existing rims. I'm running Cooper ST (mine are 10 ply, but they also come in 8 ply). However, any of the BF Goodrich/Goodyear MTR type genuine off-road (but compromise) tyres would suit your needs IMHO.
Cheers mate

my thoughts are firstly, where are you heading and secondly if i was
purchasing 4(6) i would go for good old super grippers by dunlop, for the 10 plies

I have had all terains by BFG for 10 years but the last set have had more punctures than the other 2 sets (on the gibber). i asume there has been a change to the mix.
to replace my 31 x 10 r 15 `s i will probably go to the new bridgestones not fully sure but i think 6 ply. you will need to check

Cheers Peter
every day you havent had fun is one youve missed out on

Des,
We went on a club trip recently sand driving when it came to the really soft stuff we had a cruiser with splits on it, the majority of us had to lower our pressure to around the eight to ten PSI mark, (you can imagine how soft it was), the guys with the splits had to be dragged through because it's not advisable to lower them lower than 15 psi for fear of spinning the rim in the tyre. So I suppose it depends on what sort of driving you intend to do. From what I've heard when driving on slightly reduced pressures on gravel these split rim type tyres tend to run hotter than conventional tyres. Heats not good. Don't know myself I've never used them. My opinions only

GMorn Des Chuck the splits idea and forget the grantreks and put a good set of tyres on the cruiser wheels, (and this will help grip the groung so the 100 doesnt run over big rocks !!!!!!!! LOL)

we run 12 plys for the work vehicles and you would really have to have a need for them to justify them (crap tread, get flat spots, lowere speed rating etc) however if you are going into severe country eg v rocky or cross country then they are the only way to go as they are much more puncturen resistant(they still do puncture) and changing splitties is easier

Des,

I reckon it will depend on ratio of tar: dirt/gibbers/sand etc.that you drive.

Most of us drive 75 % (plus) of our Km's on the tar. So go the tubeless rim, not split rims, for that reason. Then source top tyres (plenty of free advice about that, isn't there?!!).

I have now gone to 10 ply LT's with the straight walls. Toyo Opats. Seems to have lowered the tyre damage/punctures/rooted tyres syndrome.
My last trip was > 2500 km on dirt:
(Sandover H'way/Camooweal/Urandangie/Boulia/Birdsville/Marree)
- plenty of sticks & rocks to challenge the tyres. All up over 3t with fuel & water
(& booze). Dropped to 26 psi & 75-90kph - no worries re flatties. First time for yonks I havent had to fork out for a new tyre when I got home.Seems ST Coopers are very similar to the Opats - maybe more tread depth.

Some who have splits have ditched 'em as they are a nightmare to keep balanced. These people usually buy Sunraysias & leave their worries behind.

Summary:
keep the widies & get good tyres. Run 'em at the right pressures.

BTW - have fun!

Cheers