Lowering Height question

[nicholasmansfield]

What size lowering would look good on this old truck? Tires are 15x10 275/60/15 and 15x7 255/60/15. I measured 1 1/4” rake. I believe it has factory springs.

[cj847]

My vote is 2.5/4 on a truck if you want to drive it and not break the bank.

[SCOTI]

3/5 or 4/6.

Assuming it's a truck-arm set-up, 3/5 is as easy as swapping front spindles & rear springs w/some drop blocks & new U-bolts.

4/6 is spindles, trimming the current coils or using new drop coils. Rear would be more aggressive drop springs + some drop blocks & new U-bolts.

Watch-outs would be F & R wheel back-spacing.
It would also be a good opportunity for fresh shocks.

[1970 CST Short Wide]

Really depends on what YOU want it to look like and how much YOU want to spend. There are a Lot of options. What did the Dog say.

[72SB]

IMHO, if dropping front, I would use lowering coil springs vs drop spindles. For me, anything more than 3" blocks in the rear gets sketchy so consider "lowering springs" for that also

Then there will be DL angle adjustments to deal with. Generally, a spacer between trans and rear mount (at least 1/2") and a 2-4 degree shim with the rear blocks. You just need to measure angles and go from there

I would look into RideTech for their "progressive" lowering front coils if they make them for C10. I have them on my 67 Camaro and really like them

[dagnabbitt]

It is my impression that a 2/4 drop is the easiest thing to do first: since it can be accomplished with springs alone and is not extreme enough to affect DL.

I also think its a nice look for a LWB like yours. And if it is not low enough, keep the springs and get spindles and a flip kit later on.

[MySons68C20]

I did a 2.5" spindle drop on the front and a 4" coil spring drop in the rear.
This pic shows the finished product with an additional 1" drop block in the rear for a total of 5" drop in the back.
Please keep in mind this was all new springs etc not squatted out original equipment.

[Ironangel]

Originally Posted by 72SB

IMHO, if dropping front, I would use lowering coil springs vs drop spindles. For me, anything more than 3" blocks in the rear gets sketchy so consider "lowering springs" for that also

Then there will be DL angle adjustments to deal with. Generally, a spacer between trans and rear mount (at least 1/2") and a 2-4 degree shim with the rear blocks. You just need to measure angles and go from there

I would look into RideTech for their "progressive" lowering front coils if they make them for C10. I have them on my 67 Camaro and really like them

Actually, drop spindles are the way to go because the steering and suspension geometry remains intact. I didnt have to do anything to the A-arms or control arms, nothing is required if you use drop spindles! Drop coils change everything, shock height, steering geometry, and camber as well as toe in and suspension travel
. As long as you dont exceed 4" inches of drop in the rear you generally wont need to C-notch the frame or relocate the shocks. The panhard bar will either have to be bent slightly or replaced with an adjustable one to center the rear axle. Again, if you dont exceed 4" inches of drop or less the rear shocks and panhard bar will work. I gave my truck the 2-1/2" drop spindles up front and 4" drop springs on the rear. I bent the panhard bar and installed a set of shocks that are 3" inches shorter. I didnt have to do anything to the drive line angle because the pinon angle is still well within spec. Larger diameter wheels and tires will help with filling the obvious opening around the tires but keep in mind, larger diameter tires will change (lower) the speedometer reading...

[SCOTI]

Originally Posted by Ironangel

Actually, drop spindles are the way to go because the steering and suspension geometry remains intact. I didnt have to do anything to the A-arms or control arms, nothing is required if you use drop spindles! Drop coils change everything, shock height, steering geometry, and camber as well as toe in and suspension travel
. As long as you dont exceed 4" inches of drop in the rear you generally wont need to C-notch the frame or relocate the shocks. The panhard bar will either have to be bent slightly or replaced with an adjustable one to center the rear axle. Again, if you dont exceed 4" inches of drop or less the rear shocks and panhard bar will work. I gave my truck the 2-1/2" drop spindles up front and 4" drop springs on the rear. I bent the panhard bar and installed a set of shocks that are 3" inches shorter. I didnt have to do anything to the drive line angle because the pinon angle is still well within spec. Larger diameter wheels and tires will help with filling the obvious opening around the tires but keep in mind, larger diameter tires will change (lower) the speedometer reading...

Not necessarily. Some times wheel back spacing impacts things when using drop spindles. There is possibly a need to trim the a-arm 'gutters' in some (many?) situations.

[dagnabbitt]

Originally Posted by Ironangel

Actually, drop spindles are the way to go because the steering and suspension geometry remains intact.

That's an important consideration: but if using springs only, could you not correct the geometry changes with an alignment and new shocks? The reason I ask is because I have a drum brake truck, and I am simply not ready to put discs in front. That is a few years down the road for me.

[SCOTI]

Originally Posted by dagnabbitt

That's an important consideration: but if using springs only, could you not correct the geometry changes with an alignment and new shocks? The reason I ask is because I have a drum brake truck, and I am simply not ready to put discs in front. That is a few years down the road for me.

You can set the alignment using drop springs only.

The main benefit of the drop spindles is the travel distance of the suspension remains unchanged. When using a drop spring, it reduces the travel range of the suspension as it cycles.

For the best ride quality, you want to target the longest spring/shock combo you can fit within the mounting points.

Mild drops w/springs only are certainly possible & can function w/o issue. There are occasions where Camber alignment to era specs is a PITA but if targeting modern Camber set-points it's usually not an issue.

[Accelo]

Larger tires help the look as they fill the wheel wells better.
The advice given is valid.
Any lower and you end up having to notch the frame in the rear.
And the A arms will require work to facilitate the alignment.
You will also start ridding on the lower bumpers or worse yet the steel stops.
The short story is to go below the above recommendations requires lots more money.
Or compromising the ride quality. Which is pretty good for an old truck.
Cheers

[SCOTI]

Originally Posted by Accelo

Larger tires help the look as they fill the wheel wells better.
The advice given is valid.

Agreed. Taller tire > shorter on trucks (within reason). The parts suggestions provide multiple options which makes sense since there's more than one correct way to approach the lowering mods.

Any lower and you end up having to notch the frame in the rear.

Usually, you won't need to notch the frame (<6" rear drop). Beyond that, they're a necessity.

And the A arms will require work to facilitate the alignment.

Not sure what "work" is being referenced? Care to elaborate on this statement?

You will also start ridding on the lower bumpers or worse yet the steel stops.

This is why I always recommend spindles first on trucks. It keeps the springs as long as possible which only helps suspension travel range.

The short story is to go below the above recommendations requires lots more money.
Or compromising the ride quality. Which is pretty good for an old truck.
Cheers

Yes & no. What's that saying? Good, fast, cheap.... You can choose two.

If a guy is handy w/fab work, you can get these trucks low & still have a decent ride on the cheap. You can also get a crappy ride throwing together a poor combo of shiny new parts.

[CastIron]

I personally would leave it stock, but if I was going to lower it I'd just use lowering springs and drop it just a bit in the front, a bit more in the rear. I personally don't like lowering spindles on a truck that is going to be used anywhere besides the street. I'd rather have the extra ground clearance under the lower control arms. And using lowering springs can definitely improve the handling. There is a limit to lowering springs in the front though, if you care about proper alignment and tire wear.
Your wheels look great, by the way.

[72afr]

I've got the same size tires as you, with the exception of the wider rear rim. I have a 2.5" spindle set up front and 3" spring in the rear. As SCOTI mentioned above, I had to trim my lower A-arms to work with my rims. I recommend scouring photos and finding the look you like and go from there. Here's mine as I just need a reason to post it.

[SCOTI]

Originally Posted by 72afr

I've got the same size tires as you, with the exception of the wider rear rim. I have a 2.5" spindle set up front and 3" spring in the rear. As SCOTI mentioned above, I had to trim my lower A-arms to work with my rims. I recommend scouring photos and finding the look you like and go from there. Here's mine as I just need a reason to post it.

Good looking set-up. Very easy on the eyes.....

[OL SKOOL]

Originally Posted by 72afr

I've got the same size tires as you, with the exception of the wider rear rim. I have a 2.5" spindle set up front and 3" spring in the rear. As SCOTI mentioned above, I had to trim my lower A-arms to work with my rims. I recommend scouring photos and finding the look you like and go from there. Here's mine as I just need a reason to post it.

I wonder why some trucks are different. I have same combo wheels and tires and drop spindles. Lower a frames are not even close to touching the rim. 15x8 truck rallys front and rear. Nice truck by the way. I agree with SCOTI for sure drop spindles first no front-end geometry changes.

[Accelo]

It's all about wheel back spacing.
Unless you know the back spacing figure something like a 15X8" doesn't mean a thing.
BTW my wheels have a zero offset, no backspacing the hub is exactly in the middle of the wheel.
Cheers.

[SCOTI]

Originally Posted by Accelo

It's all about wheel back spacing.
Unless you know the back spacing figure something like a 15X8" doesn't mean a thing.
BTW my wheels have a zero offset, no backspacing the hub is exactly in the middle of the wheel.
Cheers.

'Zero offset' is 4.5"BS on an 8" wheel width. Old school math vs Metric era math is still math (for those that are unfamiliar w/the topic).

[Already Gone]

Pictured is my truck with 255/60 17 tires on 17 x 8 TT2's. Those tires are the same height as the 255/70 15's I've had on my stock height trucks. Its in the process of getting a 2 1/2 inch drop front spindle and 4 inch rear dropped spring with an adjustable panhard bar and shock relocators. Also the whole front end is being replaced with the exception of the control arms and I'm from what I've read shouldn't have any issues. Just wanting the little lower and level look I see on trucks and really like.

[67C10Step]

Another 2.5/4 drop here. Spindles in front and progressive springs in the rear. Not as slick and sexy as 72afr’s truck, maybe someday though.

[Already Gone]

Originally Posted by 67C10Step

Another 2.5/4 drop here. Spindles in front and progressive springs in the rear. Not as slick and sexy as 72afr’s truck, maybe someday though.

Great stance on the truck. Are those 275 tires front and back ?

[davischevy]

The first picture is with 2/4 drop and 17" wheels. The second is with a 3/5 drop, with 22" wheels.

[72afr]

Originally Posted by 67C10Step

Another 2.5/4 drop here. Spindles in front and progressive springs in the rear. Not as slick and sexy as 72afr’s truck, maybe someday though.

Ha! My truck's nickname should be Lucky. The stars aligned just right for this to come together the way it did. I had no business getting this result and if I were to do it today, it'd be no where close. Your build is coming along great! You just gotta leave that CJ5 alone for a bit.

[67C10Step]

Originally Posted by Already Gone

Great stance on the truck. Are those 275 tires front and back ?

Thank you. Those are 255's all the way around. I've not done the power steering conversion yet so I figured a 10" wide or so tire is all I wanted to strong arm around for now.

Originally Posted by 72afr

Ha! My truck's nickname should be Lucky. The stars aligned just right for this to come together the way it did. I had no business getting this result and if I were to do it today, it'd be no where close. Your build is coming along great! You just gotta leave that CJ5 alone for a bit.

I hear you! Truck got new exhaust last weekend and I'm starting to sort the parts I have for the power steering conversion. Still need new hoses, crank pully, and whatever rag joint I will need. Trying to get the transfer case and drive shafts back in the CJ just so I have some work bench space!