4 Inch Drop in rear, what's needed to do it right?

[Yamariv]

Hey Guys, new to the forum! I just picked up my 71 C10 to restore, Pics and more info in the intro thread I posted

https://67-72chevytrucks.com/vboard/...d.php?t=839908

Anyway, I want to do a 3 front/4 inch rear drop on my truck, not too much but just a little, I would like to keep a bit of the rake it has. I'm thinking of going with a 3 inch drop spindle in front so I keep my same suspension geometry, springs and shocks.

The back is where I'm stuck, and not sure how to do it right. I was thinking a 4 inch spring drop(I have coils, not leafs) If I do that, what do I need?

-Do I need shorter shocks or a shock relocation kit?
-Please tell me I don't need to C Notch as I'd like to keep the frame stock.
-When would I use lowering blocks on a drop?
- Is 4 inches going to screw up my drive shaft pinion angle?

Thanks in advance for any help with this!

[SCOTI]

You can use a 4" drop spring which keeps it simple.

That being said, with 4" shorter springs comes less shock travel. The drop also pushes the shock angles slightly down from their already angled placement.

Those differences are subjective. The ability for the shock to do its job correctly is compromised the shallower its installed angle is. Some notice it; others don't.

If it were my truck & I'm wanting to keep things simple BUT effectively functional, I'd do a 4" spring & get something like the No Limits Engineering rear Coil Spring shock relocator set-up. It moves the shocks outboard where they have a much better angle & offer more control of the shock + more stability since the shock is moved outboard of the frame.

The other option is removing & re-working the original shock brackets to regain some of the angle lost w/the spring drop. There are a couple of posts w/'how to' rework the stock brackets to help correct the issues in the FAQ/Suspension section on here. Re-working the stock brackets is free except for the labor to do the work.

Pick your path.....

https://nolimit.net/wp-content/uploa...k-relocate.pdf

http://67-72chevytrucks.com/vboard/s...d.php?t=451200

http://67-72chevytrucks.com/vboard/s...shock+brackets

[Yamariv]

Originally Posted by SCOTI

You can use a 4" drop spring which keeps it simple.

That being said, with 4" shorter springs comes less shock travel. The drop also pushes the shock angles slightly down from their already angled placement.

Those differences are subjective. The ability for the shock to do its job correctly is compromised the shallower its installed angle is. Some notice it; others don't.

If it were my truck & I'm wanting to keep things simple BUT effectively functional, I'd do a 4" spring & get something like the No Limits Engineering rear Coil Spring shock relocator set-up. It moves the shocks outboard where they have a much better angle & offer more control of the shock + more stability since the shock is moved outboard of the frame.

The other option is removing & re-working the original shock brackets to regain some of the angle lost w/the spring drop. There are a couple of posts w/'how to' rework the stock brackets to help correct the issues in the FAQ/Suspension section on here. Re-working the stock brackets is free except for the labor to do the work.

Pick your path.....

https://nolimit.net/wp-content/uploa...k-relocate.pdf

http://67-72chevytrucks.com/vboard/s...d.php?t=451200

http://67-72chevytrucks.com/vboard/s...shock+brackets

Thanks Scoti!

So is 4 inches in the rear generally accepted as a non C-Notch mod? Is there a better way to do 4 inches in the rear, say 2 inch block and 2 inch coils?

[mm1077]

Originally Posted by Yamariv

Thanks Scoti!

So is 4 inches in the rear generally accepted as a non C-Notch mod? Is there a better way to do 4 inches in the rear, say 2 inch block and 2 inch coils?

My sb has a 4” rear spring drop and no notch. No issues and plenty of clearance. Had the same drop on a LB that I had several years ago also w no notch and no issues.
Posted via Mobile Device

[Yamariv]

Originally Posted by mm1077

My sb has a 4” rear spring drop and no notch. No issues and plenty of clearance. Had the same drop on a LB that I had several years ago also w no notch and no issues.
Posted via Mobile Device

That's awesome to hear, thanks! Can't beat real world experience advise

When does the adjustable track bar have to be replaced when lowering?

[SCOTI]

Originally Posted by Yamariv

Thanks Scoti!

So is 4 inches in the rear generally accepted as a non C-Notch mod? Is there a better way to do 4 inches in the rear, say 2 inch block and 2 inch coils?

Originally Posted by mm1077

My sb has a 4” rear spring drop and no notch. No issues and plenty of clearance. Had the same drop on a LB that I had several years ago also w no notch and no issues.
Posted via Mobile Device

Exactly. 4" rear drop is a non-issue.

The stock shock set-up 'works'.... the suggestions regarding optimizing the shock set-up can make it better.

[LNP]

I dropped mine 4" This what I used I use a kit from CPP it had the springs, shocks, shock relocator brackets to correct the angle and adjustable track locator bar thats adjustable on both ends. I'm in Illinois so the roads here suck. We have some dips in the roads the causes the rear to slam the frame and then max out shock travel while only drivin 30mph. I am going to add a c notch in the spring to help with it. If I get on good roads it rides a nince as a brand new truck even if theres small bumps and or holes.

[CC69Rat]

As others have said 4" drop in the rear wont really put you in the position where youd need to notch the frame. You'll be ok as long as youre not hauling cattle or something in the back.

The shock relocation brackets are very cool and will just help you recover the ride quality overall. Lowering the axle closer to the frame just puts the shocks in a more horizontal position than vertical. The relocation brackets will help correct that angle. the No Limit kit is the way Id go.

I would suggest an adjustable track bar too, but that's just me. Im sure there are people out there that havent added the track bar but just sayin, I would.

Hope this helps. Good luck with it, and post up some pictures when you get finished with it.

[Grumpy old man]

This picture shows 4" drop springs with shock relocation brackets and an adjustable track bar , I've since installed 5" drop springs and swapped out the lower single shear shock mount for the earlier double shear lower shock mounts from a 63-66 chevy truck . No c notch , No drop blocks . I don't think there should be any question of using an adjustable rear track bar , We're not talking about a lot of expense to do a static drop and use good parts .

[Grumpy old man]

You don't want to use drop blocks and 15" wheels .

https://www.67-72chevytrucks.com/vbo...d.php?t=711026

[Yamariv]

Thanks guys, much appreciated!! So 4 inches shouldn't be an issue with the frame which is great news! I'm trying to go for a slightly dropped look, something that isn't too noticeable at first until you take a closer look and realized it is lowered.

I looked at my build sheet in the glove box today and noticed that I have heavy duty springs as options. Does anyone think I'd have any ride issues if I kept the stock springs up front and had new non heavy duty lowered springs in the back?

Also, what does the track bar do exactly besides keep the the axle centered? Once you drop the rear, the track bar should be changed?

[davischevy]

2" spindles w/ 1" spring in front. 5" spring, shock relocators, adjustable track bar in rear. Shorter shocks front and rear. No notch.

It rides great. I don't drive hard. On rough roads the chassis will bottom out if you hit potholes but it's a lowered truck. You have to drive it differently.

[Yamariv]

Originally Posted by davischevy

2" spindles w/ 1" spring in front. 5" spring, shock relocators, adjustable track bar in rear. Shorter shocks front and rear. No notch.

It rides great. I don't drive hard. On rough roads the chassis will bottom out if you hit potholes but it's a lowered truck. You have to drive it differently.

Nice truck Davischevy!! What does the trackbar do? Can I get away with keeping my stock one?

[LNP]

I can contest to the fact that you gotta drive different with a lowered vehicle as
I have my Challenger for 45yrs and one of the first things I did was lower it.

When you lower a C-10 the frame gets closer to the rear end. When this happens a stock track bar's angle will change and can cause the rear end to become off center. An adjustable track bar allows you to recenter the rear end so the inner or outer sides of the tires dont rub and the truck itself tracks straight down the road.

[Yamariv]

Originally Posted by LNP

I can contest to the fact that you gotta drive different with a lowered vehicle as
I have my Challenger for 45yrs and one of the first things I did was lower it.

When you lower a C-10 the frame gets closer to the rear end. When this happens a stock track bar's angle will change and can cause the rear end to become off center. An adjustable track bar allows you to recenter the rear end so the inner or outer sides of the tires dont rub and the truck itself tracks straight down the road.

Ahh makes sense, thanks for the help!

[davischevy]

Originally Posted by LNP

I can contest to the fact that you gotta drive different with a lowered vehicle as
I have my Challenger for 45yrs and one of the first things I did was lower it.

When you lower a C-10 the frame gets closer to the rear end. When this happens a stock track bar's angle will change and can cause the rear end to become off center. An adjustable track bar allows you to recenter the rear end so the inner or outer sides of the tires dont rub and the truck itself tracks straight down the road.

What he said.

[Ironangel]

I used 4" drop coils, left the shocks and shock mounts alone with no problems and I hauled a 700 lb bike with no issues. If you look at your tire clearances with the 4" drop coils you'll notice the axle is 1" to the right side of the truck. Somebody mentioned bending the panhard bar to center the axle back up so I did that and killed two birds
by gaining more clearance for the aluminum aftermarket rear diff cover. Simply hook a com-a-long from the rear edge of the right side frame rail and bend the bar back about an inch. Make the bend about 6" from the bolt in the axle. Works perfectly!

[PowerdbyChevy79]

With a 4" drop you do not need a C notch, however you may bottom out if you are hauling anything heavy, especially if you have a steel floor. My advice don't put one until you drive it and get a feel for how it drives. As far as shocks I would recommend a shock relocator kit.. the CPP ones are fine, the Tin Works/No Limit kit is better. And Install a adjustable track bar kit. that way you can make sure the rear wheels are centered.

[Yamariv]

The more I think of the 4 inch drop in the rear and dealing with possible pinion angles, new or bent track bar, new lowered shocks, shock mounts etc..I'm starting to think maybe 4 inches might be too much. A 3 inch spindle drop in the front is easy but the back sounds like a pain..

Has anyone done or heard of someone doing a 2.5 or 3 inch drop in the rear? Was it worth it or was it barely noticeable?

Although I love the really noticeable lowered look, I'd still kinda want to use it as a truck as well and not have to worry about bottoming all the time if I have a load. Maybe I should opt for 2-3 inches front and back just to get that little nicer stance and not have to worry about all the above complications.

Just thinking out loud.. Is a smaller drop a dumb idea??

[cwcarpenter98]

Another option for the rear is a 2" spring and 2" block

[Already Gone]

Welcome to the boards. I live in Saskatoon and am doing a 4 inch rear spring drop with adjustable panhard bar and shock relocators on the pictured truck.The front is getting a 2 1/2 dropped spindle. The truck with these items installed will be mobile come Spring and will be glad to meet up with you so you can see the stance and come for ride to see how she feels. Before u go dropping the truck if you do not have one on the truck I highly recommend you get a front sway bar on the truck and if u search this website there are lots of threads on front sway bars. Also decide which size rims/tires you are going to use.

[Greasey Harley]

I lowered my rear 5" and can still haul stuff.
CPP -4"-HD springs, 1" blocks, adjustable track bar, CPP shock relocation brackets, KYB shocks.
No c notch, but I did have to trim my bump stops quite a bit.
The HD springs do offer a firm ride, but it's not overly harsh for a lowered truck.
I also added a 3/16 aluminum shim on the left rear corner to counteract the notorius "Chevy lean".
It will still haul a full dress Harley, no problem.

[Yamariv]

Originally Posted by cwcarpenter98

Another option for the rear is a 2" spring and 2" block

That's interesting! So would that mean I could get the 4 inch drop but keep the stock sized shocks and not really have to mess with anything else back there?

Any drawbacks you can think of? I guess your trailing arms would be closer to the ground than a 4 inch spring drop, not sure if that matters though?

[Yamariv]

Originally Posted by Already Gone

Welcome to the boards. I live in Saskatoon and am doing a 4 inch rear spring drop with adjustable panhard bar and shock relocators on the pictured truck.The front is getting a 2 1/2 dropped spindle. The truck with these items installed will be mobile come Spring and will be glad to meet up with you so you can see the stance and come for ride to see how she feels. Before u go dropping the truck if you do not have one on the truck I highly recommend you get a front sway bar on the truck and if u search this website there are lots of threads on front sway bars. Also decide which size rims/tires you are going to use.

That's a friggen beautiful truck Already Gone! That's an amazing offer and I'm totally up for a ride when the weather gets nice for sure. That would be great to see yours in the flesh and get a feel for how the stance is in person! Yours sits pretty much like mine does height wise. Mines got the heavy duty springs on the build sheet options though so I'm not sure how that would affect things if I kept the stock springs. I had 700lbs of insulation in the bed this morning and the truck barely squatted an inch lol.

I was originally going to do the drop right away while I do the brakes, suspension and shocks but I like the idea of holding off on the drop for a little bit and enjoying the truck while I do the rust work is a better way to go for this winter.

Front and back sway bars or is the front mostly the one worth doing?

Ugh, the tires question.. I have no idea yet. I really like the stock look or ralley wheels but I may go more custom and modern down the road once I eventually do the paint.

[Yamariv]

Originally Posted by Greasey Harley

I lowered my rear 5" and can still haul stuff.
CPP -4"-HD springs, 1" blocks, adjustable track bar, CPP shock relocation brackets, KYB shocks.
No c notch, but I did have to trim my bump stops quite a bit.
The HD springs do offer a firm ride, but it's not overly harsh for a lowered truck.
I also added a 3/16 aluminum shim on the left rear corner to counteract the notorius "Chevy lean".
It will still haul a full dress Harley, no problem.

Thanks Greasey Harley, super valuable info!! I was throwing around the HD lowering springs in the back idea so I could still use it as a truck. Awesome to hear from someone who has them. When I lower, I think I might go that way so that they match my front stock HD springs as I'll just be doing the spindles in the front.

Which HD rear springs did you use? I had found some but am having a hard time finding them again.