3.5/5 drop questions about usability of truck

[NC67Chev]

It’s been a while since I’ve been active on here. I’m thinking about shaking things up a little, but looking for some feedback. Can you haul anything at all with a 3.5/5 drop (drop spindle + 1” lowering spring in the front) and 5” drop spring in the back? It’s not like a haul anything real heavy, but maybe an occasional load of brush, etc. Thanks for your help!

[HO455]

I have one inch drop springs on my Burban without the dropped spindles. The spindles won't affect the load capacity or suspension travel compared to mine. (The dropped spindles will reduce ground clearance of the lower control arms.)

You may run into problems with 5" drop springs in the rear with a load bottoming out on the frame bumpers. If you're only hauling occasionally then a set of auxiliary air bags would be a good addition. You may also want to look into 2" drop blocks and 3" drop spring to get your 5 inch drop.

I am always hauling stuff or pulling trailers with mine. I have air bags without springs in mine.

[hewittca]

From experience, I've had trouble hauling with my truck and 5" drop springs from CPP. Those springs always felt a bit on the soft side even just cruising around. Here's my old truck with 5" drop springs completely bottomed out from one scoop of dirt.



On my current truck I went with the 4" HD drop springs from CPP with 2" drop blocks. This combo works much better for hauling stuff. It's still doesn't have the load carrying capacity of stock springs, but it will definitely handle more than the 5" springs.

[HalfBrit]

Before I decided to turn my truck into an never ending Lego kit (frame off), I had the same drop values on my '70 (drop spindle/1" & 5"). I regularly hauled my motorcycle/ramp/gear & tools to the track. That totaled aprox. 750lbs. I did trim my axle bumpers. The rear springs I used were Eibach, 1/2 ton rated springs. Can't remember the part #.

[NC67Chev]

Thank you for the replies! It’s also nice to hear from a couple of local folks! I’m not sure I’m interested in using blocks, so I’ll have to stew on that a little more. I’m also looking at new tires in either 16” or 18” (undecided on that). Anyway, with a 3.5/5 drop, do you guys think a 28” tire or 29” tire would be best?

[OregonNed]

I'm sure happy with the stance on my '68 - 2" springs and 2" spindles in front - 3" springs and 2" blocks in back. But as far as hauling I can't do much - bed is too nice, and supposedly collector plates in my state prohibit hauling (but shouldn't matter - blatant speeders and red light runners are never pulled over that I see - so why a truck with a load?)

[special-K]

I want to haul and the chassis I bought has 4/6 drop. I also like to have the option of a rake sometimes. So, I'm going with auxiliary Air Lifts (1500# added capacity) that also give adjustable ride height by how much air you add, like how air shocks work... but give a better ride than those

[hewittca]

Originally Posted by NC67Chev

Thank you for the replies! It’s also nice to hear from a couple of local folks! I’m not sure I’m interested in using blocks, so I’ll have to stew on that a little more. I’m also looking at new tires in either 16” or 18” (undecided on that). Anyway, with a 3.5/5 drop, do you guys think a 28” tire or 29” tire would be best?

What are your reservations about blocks? They are a commonly used and reliable way to build in a 2" drop to your truck without touching the suspension. With a 5" drop, you are still going to have a lot of wheel well to fill so I would go 29". I have an 11" drop in the rear of my truck and I'm running a 29" tire.

[NC67Chev]

Originally Posted by hewittca

What are your reservations about blocks? They are a commonly used and reliable way to build in a 2" drop to your truck without touching the suspension. With a 5" drop, you are still going to have a lot of wheel well to fill so I would go 29". I have an 11" drop in the rear of my truck and I'm running a 29" tire.

Probably lack of familiarity. I wonder which would be best: 1. 4” drop HD springs (like mentioned above) plus a 1” block. Or: 2. 3” drop springs plus a 2” block?

[3767]

I have had a 3/5 drop . The front was 2.5 drop spindle and 1 in spring. The back was all spring. I wouldn’t do it that way in the rear again. The block /spring combo is better. U can haul a small load but like it was shown, just a simple 1 scoop of dirt and you are bottomed out. But a light load like you mentioned would not hurt anything. Also…you will need an adjustable trac bar. You will want to think about a shock relocate kit for the rear. This will help with the ride quality. You will need to trim the rubber stops down. This will help with the bottoming out part. Best of luck on your decision. Keep us all posted on what you decide .

[NC67Chev]

Originally Posted by 3767

I have had a 3/5 drop . The front was 2.5 drop spindle and 1 in spring. The back was all spring. I wouldn’t do it that way in the rear again. The block /spring combo is better. U can haul a small load but like it was shown, just a simple 1 scoop of dirt and you are bottomed out. But a light load like you mentioned would not hurt anything. Also…you will need an adjustable trac bar. You will want to think about a shock relocate kit for the rear. This will help with the ride quality. You will need to trim the rubber stops down. This will help with the bottoming out part. Best of luck on your decision. Keep us all posted on what you decide .

What size tires do you have with your 3.5/5 drop? Any chance you can share a side picture of your truck?

[tutone]

Two different approaches. The Ochre 72 swb , 2.5 drop spindles andI cut 3/4 of a coils off. Gave me 3 - 3 1/2 or so. The rear was a one inch block and 4 inch springs.
The one I have now sits almost exactly like it, Western chassis 3/5 all springs. Truck drives amazing but I have only hauled brush in it. The other truck was usable as a truck. It never bottomed out on me. Here are a couple of pictures for reference.
Edit. Tires on both trucks
Front....235 70 15
Back.....235 75 15

[indymachinist]

I must be missing something… my rear drop is 6” all spring. It rides and drives great. What makes a drop block better?

Honestly I choose the spring route because I was not interested in a drop block. In my mind I didn’t like the idea of the axle being further away from the truck arm. I was worried that could potentially cause a problem with the longer U bolts and additional leverage against the truck arm.

I haven’t tried to haul anything yet but before I do I intend to add helper air bags as special-K mentioned.

[hewittca]

Originally Posted by indymachinist

I must be missing something… my rear drop is 6” all spring. It rides and drives great. What makes a drop block better?

Honestly I choose the spring route because I was not interested in a drop block. In my mind I didn’t like the idea of the axle being further away from the truck arm. I was worried that could potentially cause a problem with the longer U bolts and additional leverage against the truck arm.

I haven’t tried to haul anything yet but before I do I intend to add helper air bags as special-K mentioned.

It's not so much that 5 or 6" springs are bad, just that if you try to haul anything with them they are not really designed for that. Those springs have lower spring rates compared to the stock springs. They are meant for cruising around, not hauling. If you want to still haul something it's best to go with a shorter drop spring and blocks. CPP makes a HD 4" drop spring that I have in my current truck and I can load the bed up with no problem. Drop brocks are a tried and true way to drop the rear of your truck with negligible change in suspension geometry. The u-bolts that come with the block kits are usually well made. I've never heard of any failing. And the portion of the trailing arm where the rear end mounts is close to level so drop blocks aren't adding much leverage of the rear end against the truck arm.

[special-K]

What I don't like about blocks is lower scrub line. I believe in Air Lift auxiliary bags as the best way to get everything you could want without anything sacrificed. And for me, sometimes I like level (4/6) and other times I want the rake (4/4) as was popular in these truck's era, which is the theme of my '67

[hewittca]

Yes special-K, scrub line is definitely the one drawback to drop blocks. If you are running anything larger than 15" wheels then it doesn't matter. With 15" wheels you are very close, if not over, the scrub line and run the risk of dragging components when you lose a tire. Here's an example on my truck with blocs. The blue line is if you lose one tire. On my setup, my u-bolt will just barely be hitting the ground. The red line is if I lose both tires and in that case I am screwed!

[3767]

Tire size for mine was 255/60/17. 29 in tall.rims are 17x8. Still plenty of room. U will want to spend some time looking tires and their sizes. Some sizes don’t have a lot of choices and are higher n price. The blocks and the u bolts that come with them haven’t had a problem of breaking that I have ever seen or heard of. Most people don’t have that kind of power under the hood to start with .

[HO455]

Originally Posted by hewittca

Yes special-K, scrub line is definitely the one drawback to drop blocks. If you are running anything larger than 15" wheels then it doesn't matter. With 15" wheels you are very close, if not over, the scrub line and run the risk of dragging components when you lose a tire. Here's an example on my truck with blocs. The blue line is if you lose one tire. On my setup, my u-bolt will just barely be hitting the ground. The red line is if I lose both tires and in that case I am screwed!

Scrub line. I learned a new term today. Thanks!

The overall loss of ground clearance (even with fully aired up tires ) is why I'm not running blocks or drop spindles on my Burban. My S10 Blazer has both and it doesn't take much of a rut in the road before it starts dragging. There's a couple of spots of bad asphalt around town that I have to drive carefully over or I'm scraping a control arm. Or if your driving in 4 inches of snow it starts collecting under the truck just waiting to highcenter you. Some drop spindles don’t work with15" wheels due tie rod interference. Although I believe that is fairly common knowledge I thought I should throw it out just in case.

[tutone]

I've been guilty of violating the scrub line rule, but not on any truck.
Especially one that I might haul with. On the 72 in my above post, I used a one inch block. It still kept me above the "line" by at least 3/4 ". 2/4 drops are common and I had most of the crap laying around to cobble a good drop together. I had to buy a block and two spindles. It was a better stupthan springs for sure. I think I trimmed an inch or so off the u bolts too.

[Richard]

Helper bags for the win on a dropped truck. Had an 8" drop on the rear of my 94 and hauled lots of fairly heavy loads with the helper bags. Rear was dropped with 2" de-arched leafs and a flip kit. Added bonus is running 10-20 psi in bags unloaded adds dampening to the leafs and makes ride smoother.

[NC67Chev]

Thanks everybody for your thoughtful replies and for sharing your experiences. I’m leaning towards the 2.5/4, but not 100% there yet. I’ve seen a lot of trucks through the years with that stance, which I like. I do like the look of 3.5/5, but it does seem to complicate things a little more.

[LS short box]

I went with 4/6 drop on my 68. 2.5 spindles/2" springs in the front. 4" springs and 2" blocks in the rear. I had a C-notch in the rear. 20" wheels so scrub line was not a problem.
Most weight I ever had in the back was a cooler and a couple of folding chairs. It rode well. It had more ground clearance than any of my Camaro or Firebird hot rods.

[special-K]

4/6 has always been the most common static drop. No issues really, except getting into actual pickup use, meaning a decent load. Guys trim the bump stops to gain better clearance against bottoming. That's why I believe in the auxiliary bags the sit inside the springs. They can both or either raise the rear for a load or just add spring capacity to resist sag with a load. With 4/6 drop I can ride level or add air for the 4/4 rake, same rake as stock. Both for a different stance and for better load capacity. You can also get air bags that fit in place of the coils for a really wide range of stances and load capacity

[Palf70Step]

Originally Posted by hewittca

What are your reservations about blocks? They are a commonly used and reliable way to build in a 2" drop to your truck without touching the suspension. With a 5" drop, you are still going to have a lot of wheel well to fill so I would go 29". I have an 11" drop in the rear of my truck and I'm running a 29" tire.

Only issue with 2" blocks is if you get a flat, the ubolts will drag the ground with 15" wheels. Other than that, I prefer them over springs. If I do mycurrent truck, I'd use 1 1/2" block and maybe 2" springs in rear since I plan on keeping 15" rims.

[LNP]

I used 2" drop spindles and 4in drop springs in the rear. I ended up having to cut the front springs for a inch more drop because the front was higher than the rear. What I did so I could pull my trailer for some light hauling was installed air shocks. Worked out real well.