[NorCal 4x4]

I'd pass on the Dura-Grapplers since they are a hwy. tread. They'd be fine on dirt roads, but don't have the traction of an AT.

The Nitto Terra Grapplers are a good AT, as well as the BFG AT KO and the Toyo, (Toyo makes Nitto). Many sizes in the BFG AT KO have the severe weather rating which means they are sometimes exempt from snow chain controls.

These are offered in light truck, (LT), sizes, which are tougher than the P-metric ATs like the Bridgestone Revo, (some of their smaller sizes are offered in a LT). The LT's stiffer side walls roll under less in higher speed cornering which is a big advantage for on road, and the LT sizes have greater load capability, but only at inflation pressures approaching their maximum.

How wide are the Helos and what's their offset or backspacing?

Nitto Terra Grappler:
LT275/70R18 E 125S 200-910 15.6 33.27" dia. 10.94" width on an 8" wide rim, and about 11.2" width on a 8.5" rim. 7.0-(8.0)-8.5
LT285/65R18 E 125R 200-810 16.5 32.52" dia. 11.22" 8.0-(8.5)-10.0
The 1st one above, the 275, shouldn't be mounted on a rim greater than 8.5"

BFG AT KO:
LT285/65R18/E 125R RWL 67553 8 - 10 11.5" on 8.5 32.7" dia.
LT305/65R18/E 124R RWL 35237 8.5 - 11 12.2" on 9 33.7" dia.

Toyo Open Country AT:
LT285/65R18 125S E/10 300630 8.0-8.5-10.0 57 17 32.5" dia. 11.4" on 8.5 width rims.

For a level kit contact PRG. Contact info. at PRGproducts.com