Hooker,
Thanks for your good input.
To me, the IFS is better suspension when driving on rough roads, especially those full of washboard. I have had 3 IFS rigs and one straight axle--and driven some others, and it was amazing how much faster and more comfortably I could drive over rough roads with IFS than I could straight axle rigs.
My straight axle Surburban was certainly easier and cheaper to lift, but with the Superlift Superride springs I initially installed, there was hardly any front suspension travel. I had to literally crawl over rough stuff to keep my head from bouncing into the headliner. When I changed to Skyjacker soft ride springs, it was a little bit better, but no where near as smooth as my Z-71s. My 2500 HD isn't quite as good as my 1/2 ton Z-71s, but it is way better than my 1/2 ton Surburban, even with the Skyjacker springs.
However, I agree the IFS is not as good for serious off roading, if for nothing more than it won't give you very good steering component life if you use tires more than 35s, and serious off road tires on large pickups seem to start at 35s.
They all tell me the HD front suspension is beefier than earlier GM IFS rigs. The HDs also have the GM 14 bolt rear which is legendary in it's durability and strength. I'm not sure that not gaining any more wheel travel with a GM IFS is that much of a concern, as there is a decent amount movement in it's stock form. The issue is the tiny wheel wells GM built into this truck, and to even run 285s on 8" rims you need at least 4" of lift to have decent clearance.
I guess it's all a matter of picking what compromises you want to deal with. Since the majority of my four wheeling is going to and from hunting/fishing on sometimes rough "washboardy" logging roads, along with some hauling and towing on roads of all conditions, I like the smooth ride of the IFS. However, I am able to live with 33" tires (315s max). My understanding is that 35s are probably okay on an HD IFS, but certainly nothing larger if the truck gets driven off the pavement on a regular basis.
You are the first one that has mentioned problems with rear lift blocks, but then again you are probably talking about many different kinds of trucks of varying heights while I am talking of HDs with a 4" lift block. The lift kit companies seem to think a 4" block is not that big of an issue with the HDs. However, traction bars are a very popular option for these trucks, and given the amount of HP and torque a DMax is capable of, it is an issue to consider. My own truck's chip will put down 380 HP and 820 ft lbs to the rear wheels on 245s.
Which do you think is better, a lift block and traction bars, or just a new rear spring? So far, the companies that offer rear springs as a lift option for the HDs say the ride is rougher with the springs than the blocks.
Blaine
