150K miles on truck--suspension thoughts?

I've done a lot of research on upgrading the suspension on my 07 access cab 4x4 V6 truck. I've had the truck since new. I had the rear spring TSB done right before it hit 36,000 miles about 7 years ago. I'm over 150K miles right now. The shocks are needing replaced--its getting a bit jerky hitting potholes at highway speeds. My rear springs are NOT sagging bad, leading me to believe I don't need full new leaf packs.

I'm wanting to go up to a 265/75/16 tire. I'm still running 245's. I recently put a camper shell on my truck. I may have lost 1/2" in the rear when installed, but the springs are still holding up.

I'm considering a 3-leaf progressive AAL in the rear/5100's + 5100's up front set at 0.85". I really want to avoid vibes and figure this is my best bet. I occasionally haul firewood and think the progressive AAL is the best bet.

Thoughts? It seems that everyone that does an AAL goes to 1.75" on the front 5100's, but I'm scared of the vibrations, especially with a truck that has 150K+ miles. I don't mind the "rake" look, but don't want it to look like a dragster. I'm hoping that the weight of the camper shell will net me a 1" lift in the rear and that will match well with 0.85" up front.

Feel free to bash me if this has been covered, but I believe my situation is somewhat unique in that the truck is high mileage and the rear TSB springs aren't frowning.

 

I'm open to opinions. I gather that keeping it installed yields an extra ~1/2" of lift and increases carrying capacity, but it seems to be largely debatable how much it increases your carrying capacity. I'm sure I could live with it either way.

 

I'm preparing to take the plunge myself, though my truck is only 2 years old with 30k on it. What I'll share is worth what you paid for it(nothing) as it's just regurgitated information I've gathered. Even though I like the look of a level truck I want to keep some rake as I routinely load my truck with 900+ lbs of people and camping gear in addition to the weight of my canopy. Currently when loaded for camping my truck sits almost level with a full tank of gas. I think if I skipped the AAL there would be sag.

The TRD Pro, a factory assembled "level" truck has 1.75" in the front over a stock truck. The 3 leaf AAL(which is what I'm planning to use) is good for 1.5" over stock. Thus I think based on this it's safe to say 1.5" to 1.75" won't be an issue. Many folks here have no problems with vibes under 2.5", though caster get to be an issue for anything over 2". Granted the TRD Pro doesn't have anything done in the rear so it sits level, but if anything keeping the factory rake will be good for caster.

Based on the above I've determined for my uses a coilover or Bilstein 6112 set at between 1.5" to 1.75" is ideal when paired with a 3 leaf AAL. I may go a step further and throw Ride Rites in as well.

I figure worst case by keeping it below 2" I may only need the ECGS axle bushing. The install looks pretty easy for anyone who's mechanically inclined. By keeping the factory rake and limiting the lift I doubt there will be any issue with driveline vibes.

 

randomguy--interesting thoughts. I did not know that the TRD Pro comes with an extra 1.75" up front. Can anyone comment on whether nor not other geometry is different from the factory for TRD pro models, or if it is just a standard Tacoma front end w/1.5" of lift?