What size drop without a C notch?

[r8rs4lf]

1972 C10 Highlander w/350/350, PS, PB, factory AC/heat

Ready to purchase a drop for my truck, but I do not want to add a C notch. Also not looking to be in the weeds, just something to take up some of the gap in between the tire and fender.

I have a leaf spring suspension in the rear, no trailing arms and I will not convert over.

I plan on purchasing 2.5 drop spindles for sure.

For now I plan on running 235/75/15 tires.

No towing or hauling. Only a chair and cooler in the bed.

I've been thinking about a 3.5/5 drop.

What size drop will net me the best ride quality without bottoming out and NO C notch?

Please add your experience. A pic of it would be nice.

TIA

[r8rs4lf]

So I went under my truck to check clearance from the frame to the bump stop.

Frame to top of bump stop is about 4 3/8".
Frame to that perch (looks like the first point of contact) where the tape measure is, is <6"

If I do a 5" drop, that would leave me with <2" of travel before the frame comes in contact with that perch taking into consideration there is no sag on this 54yo suspension.

Ideally, how much clearance should there be between both contact points?

Pics are sideways again.

[SCOTI]

Originally Posted by r8rs4lf

So I went under my truck to check clearance from the frame to the bump stop.

Frame to top of bump stop is about 4 3/8".
Frame to that perch (looks like the first point of contact) where the tape measure is, is <6"

If I do a 5" drop, that would leave me with <2" of travel before the frame comes in contact with that perch taking into consideration there is no sag on this 54yo suspension.

Ideally, how much clearance should there be between both contact points?

Pics are sideways again.

Too many variables for one right answer.

Given years of experience w/these old trucks, I'd say you want/need @ least 3" of travel before making contact. That would likely be fine for ~75% of normal driving situations. Jacked-up roads where you live? You'll def want as much clearance w/o contact as possible.

You reference an image of the rear-end axle tube to the frame rail..... That's not the only clearance issue. Did you measure between the differential & the bed floor? What's that number? With mild drops it's usually not an issue but it's a dimension you should know the answer for when making decisions.

The location of measuring matters. You show a measurement from the base where the bumpstop mounts to the bottom of the frame rail but it sure looks like that mounting base is lower than the top of the axle tube.

I'm also seeing only 3-leafs.... If you purchased 'dropped leafs', how many leafs are in their set-up?

[Sunchild714]

I have a 4/6 Western Chassis drop without a c-notch https://westernchassis.com/1965-72-C...-Lowering-Kit/. It's pretty close, but no bottoming out. Challenge has been finding better shocks that work and fit. I settled on a set of CPP shocks all the way around. Not the best ride but it works.

[WHYBYNU]

I did a 4-6 drop almost 20 years ago without a c-notch I've probably bottomed out 1-2 times at the most on really scrappy roads.

[KQQL IT]

Flip it
Cut a coil
Drop spindle

Perfect

[SCOTI]

Coil vs flipped leaf = 2 different scenarios guys. He stated he wants a mild drop & I would not call 4/6 or 5/7 mild. Mild is 2.5/4 or 3/5 max in my book.

Previous trucks I've been involved with did have issues w/making contact @ the frame (no bumpstop; no c-notch builds).

[dagnabbitt]

You can do 2/4 with springs alone, I have been told. With leafs in rear get some axle blocks. It's a cheap and reversible way to see if you like the ride height without making it complicated, too.

I've never met anyone who said they went too low and that they regret it. But that is a nice original truck, a mild drop would look great.

[c30]

That really depends on how big the cooler is. Twenty cases of cold beer on ice could get pretty heavy.

[r8rs4lf]

Originally Posted by SCOTI

Too many variables for one right answer.

Given years of experience w/these old trucks, I'd say you want/need @ least 3" of travel before making contact. That would likely be fine for ~75% of normal driving situations. Jacked-up roads where you live? You'll def want as much clearance w/o contact as possible.

You reference an image of the rear-end axle tube to the frame rail..... That's not the only clearance issue. Did you measure between the differential & the bed floor? What's that number? With mild drops it's usually not an issue but it's a dimension you should know the answer for when making decisions. I did not measure between the diff and floor. I will get under there and measure though. This is my first go around with this so I appreciate your patience.

The location of measuring matters. You show a measurement from the base where the bumpstop mounts to the bottom of the frame rail but it sure looks like that mounting base is lower than the top of the axle tube. You are correct. So if I remove the bump stop, the frame will hit that "perch" on the other side of the bump stop mount first. In my second post with the measurements I refer to that as a "perch." Not really sure what that is, but it looks like it's part of the bump stop mount that wraps around the axle tube.

I'm also seeing only 3-leafs.... If you purchased 'dropped leafs', how many leafs are in their set-up? According to the CPP site it comes with 4 leafs.

5" drop leaf springs here

Because there are soo many trucks out there with different results, I'm starting to think that I may have to just add the drop, see where it lands and drive it around for a bit to see if I'm happy with the clearance. If not, I would have no other choice but to add a C notch. That seem like the logical way of going about it.

[r8rs4lf]

Originally Posted by Sunchild714

I have a 4/6 Western Chassis drop without a c-notch https://westernchassis.com/1965-72-C...-Lowering-Kit/. It's pretty close, but no bottoming out. Challenge has been finding better shocks that work and fit. I settled on a set of CPP shocks all the way around. Not the best ride but it works.

Originally Posted by WHYBYNU

I did a 4-6 drop almost 20 years ago without a c-notch I've probably bottomed out 1-2 times at the most on really scrappy roads.

Nice trucks! How did both of you achieve a 4" drop in the front? Was a 2" drop spindle made back in the day? My options are 2.5" drop spindles and lowering springs in 1" increments. So it's a 3.5" or 4.5" drop.

Originally Posted by dagnabbitt

You can do 2/4 with springs alone, I have been told. With leafs in rear get some axle blocks. It's a cheap and reversible way to see if you like the ride height without making it complicated, too. From what I understand, the rear end needs to be flipped to use lowering blocks correct?

I've never met anyone who said they went too low and that they regret it. But that is a nice original truck, a mild drop would look great. That's exactly what I'm shooting for.

The roads here change drastically. Some cities have smooth streets while others are f'n terrible.

[SCOTI]

I did not measure between the diff and floor. I will get under there and measure though. This is my first go around with this so I appreciate your patience.[/I][/B]

No worries. I feel it's typically not an issue until you get over 4" of rear drop. Since you're starting out somewhere in between (not 100% stock & don't know exactly what's been changed) it's something to keep in mind as you're making changes.

You are correct. So if I remove the bump stop, the frame will hit that "perch" on the other side of the bump stop mount first. In my second post with the measurements I refer to that as a "perch." Not really sure what that is, but it looks like it's part of the bump stop mount that wraps around the axle tube.

The top side of the axle tube is higher than the bump stop perch. You need that dimension in mind as you plan for lower w/o worry of contact.

According to the CPP site it comes with 4 leafs.

Probably correct which is again why I stress making your decisions off of where you are now.

And to answer another question of yours in other post..... 4" of front drop is commonly from using Squarebody based 3" spindles & a 1" spring. Many guys will say '4/6' or '5/7' drop based only on a kit & not any actual recorded dimensions. They just know it dropped somewhere in that ballpark amount.

Again, since things have been changed, you need to decide things KNOWING your starting dimensions or there's a possibility of doing things twice.

[WHYBYNU]

Thanks for the compliment. I guess to be correct 4.5 front drop 2.5 spindles 2" drop springs on the front. In the rear 5" drop springs 1" blocks.When I went to Wilwood disc brakes used same drop springs but had to switch to 2.5" drop modular spindles on the front. Hope that helps..

[r8rs4lf]

Originally Posted by WHYBYNU

Thanks for the compliment. I guess to be correct 4.5 front drop 2.5 spindles 2" drop springs on the front. In the rear 5" drop springs 1" blocks.When I went to Wilwood disc brakes used same drop springs but had to switch to 2.5" drop modular spindles on the front. Hope that helps..

So I assume you started with drums up front?

I have factory disk so I don't think I need the modular spindles. Correct me of I'm wrong.

[SCOTI]

Originally Posted by r8rs4lf

So I assume you started with drums up front?

I have factory disk so I don't think I need the modular spindles. Correct me of I'm wrong.

Modular spindles are used for a variety of reasons:
*They are said to not increase track width (drop spindles do).
*They are ready for big-brake caliper brackets vs having to modify regular disc brake drop spindles.

[KQQL IT]

Originally Posted by SCOTI

Coil vs flipped leaf = 2 different scenarios guys. He stated he wants a mild drop & I would not call 4/6 or 5/7 mild. Mild is 2.5/4 or 3/5 max in my book.

Previous trucks I've been involved with did have issues w/making contact @ the frame (no bumpstop; no c-notch builds).

I thought i read it was a leaf truck..

[SCOTI]

Originally Posted by KQQL IT

I thought i read it was a leaf truck..

It is. One of the other responses was a link to a 4/6 coil spring drop though....

I told him he needs to get some dimensions so we can help determine where a flip-kit would put him as far as height & clearance. With the spring pack shown in his images (I counted 3-leafs), it didn't come from GM that way so it would be just a guess if flipping the axle will still allow clearance. I feel an informed guess is a better approach since he wants a decent ride & does not want to cut the frame.

[Richard]

Not hard to see the results of an axle flip here as the dimensions are posted.. Drop will equal the axle plus the pad under it. Bump will be against frame. As existing spring specs are not known. Any other options are a guess. The diff would most likely not hit unless frame is notched.

[SCOTI]

Originally Posted by Richard

Not hard to see the results of an axle flip here as the dimensions are posted.. Drop will equal the axle plus the pad under it. Bump will be against frame. As existing spring specs are not known. Any other options are a guess. The diff would most likely not hit unless frame is notched.

Again.... This is why I suggested he get out & take measurements. From the images provided it appears an axle flip would be too much but it's possible the images skew accuracy. Actual numbers from a tape measure will help narrow what options he should consider.

[Extended Power]

I also have rear leafs.
I went with 3” dropped A-arms in the front, keeping the stock springs.
I removed all but three leafs in the rear and installed 2” drop hangers.
Front and back are on 20” wheels.

The second picture had the camera crooked....look at the wall slats in the background.
I would like to drop the front another 2” and install a Wilwood Pro spindle a-arm setup, but they are a 2 1/2” and I think that would be too much.

Also...I installed a sway bar in the front as my truck did not come with one, and I see that the end bushings are hitting the top of the crossmember before the bump stops. No marks at all on the bump stops, but you can definitely see where the bushings have been hit.