67 C10 Lowering + Wheel/Tire Sizes and Other Recommendations

[laketboy]

New to the C10 forums(s). Seems to be no shortage of interest in the 67-72 C10 with 3-4 forums on the Internet.

My son has recently acquired a clean straight 1967 C10 long bed (and purchased a used/running LS engine and trans for it. A local guy who is very experienced with C10's has chopped the frame and bed to convert to short bed. As expected, I've spent a couple of hours searching the 3 major C10 forums and learned a lot, but would like some suggestions in the area of suspension drop, ride height, wheel and tire sizes and parts and or kits that get the job done on a modest beginner budget (read: not the cheapest way to go, not the BEST/MOST expensive).

Basics: He does NOT want the LOWEST drop possible. He wants to actually use the truck occasionally to haul basic stuff. Seems what I've read tells me the stock rear is 2" higher than front and most popular drops are front/rear drops of 2/4", 3/5" and 4/6" to achieve "level" truck". He seems to be aiming at the 3/5" drop based on recommendations by guy doing some of the work. Plans are to go with 5 lug on all 4 and disc brakes (at least up front). Interest in wheel diameters between 17" and 20" (old school dad prefers 17-18, but has 20" on new 2016 Silverado levelled with 1.75" front rise using Bilstein adjustable to level)

All this said, what are some suggestions of HOW to do this? 2/4" drop vs 3/5" drop pros/cons? Parts and work required for either? What (max) wheel and tire size combos work to fill wheel wells for both 2/4" and 3/5" drops without rubbing issues?

I've read very BUDGET ways to do things and EXPENSIVE (BEST?) ways to do all this. I don't think airbags are in the budget at this time, BUT if able to acquire good USED (craigslist and eBay are great), maybe.

BTW, I've found the following suppliers with seemingly top notch ($$$) products
http://www.earlyclassic.com/
http://www.classicperform.com/
http://www.lmctruck.com/features/cb/cbal1.htm

Summary
2/4" vs 3/5" drop parts required
Max Wheel/Tire sizes for either 2/4 and 3/5 drop
Disc brake recommendations
Steering component change recommendations
LS engine/trans mount recommendations

Thanks in advance for your recommendations based on experiences

[68Stepbed]

First off, I would only use Early Classic for regular drop parts. I used CPP in the past, and wasn't pleased with the product or the customer service. Mark and Stan at ECE have always took great care of any questions I had.

As for the questions on drop, the 2/4 will be the easiest as it's just a matter of swapping springs. An adjustable panhard bar is highly recommended to center the rearend.

The 3.5/5 requires 2.5" drop spindles and a 1" drop spring. However, some companies offer 3" front drop springs. It's been debated that any more than a 2" spring in the front causes alignment issues and the possibility of the spring popping out of the pocket if the suspension is unloaded, like during a bad pothole of speed bump. But, there's still many who run this setup and claim no issues. I personally don't have experience in the 3" front drop spring area.

If dropping more than 4" in the rear, most companies offer a different panhard bar. ECE calls theirs the Super Track Bar kit. It mounts in a different location, just above the trailing arm mount, to recorrect the geometry. Once the rearend move past a certain point, the original panhard bar is at the wrong angle and causes odd driving characteristics.

My only complaint with ECE is the KYB shocks included with their kits. They're just not the correct length shocks for the lowered application. There's actually a thread about it on here somewhere. ECE actually put RideTech shocks on their own personal trucks. But since you're on a budget, I wouldn't recommend those.

As for the brakes, you will have to have disc brake spindles to add disc brakes, so that may possibly help in the decision of which drop kit. Again, ECE is a one-stop shop, as they offer quality, American made, disc brake components with everything included for the installation. They also offer the disc conversion in 6 lug so he wouldn't have to change wheels and convert the rearend or axles.

Steering components are unaffected. But if it doesn't have power steering, this would be a good time to upgrade that.

LS swap components have many varieties. I personally used the Performance Online tubular engine stands, and Energy Suspension mounts with an adapter plate. The trans crossmember is from ECE, but even a stock auto trans crossmember will work.

I think that's about all I have right now. Let me know if you have any more questions. I'll be glad to help.

[laketboy]

Thanks Matt! Exactly the type of info I was looking for. BTW, beautiful 68 short bed step in your profile pic. Color is a shade lighter, but reminds me of my 02 Z06 Corvette Electron Blue. Back in the late 70's I had a 56 short bed step with wrap around glass, but didn't have the means to do a proper resto-mod project and sold her.

So, I assume your 68 step is dropped 2/4", correct? I think that is the look and ride height he's looking for. ALSO, what size wheels and tires are you running fore and aft? That would also help immensely!

Thanks again
Keith

[PanelDeland]

I did a 2 1/2-4 drop. Since this was also a disc upgrade the spindles are 2 1/2 drop ones and I didn't need much change to get the alignment back. 4 in drop springs on back. I still need to relocate the shocks, but the panhard is 50/50. In other words, it works OK but I will be changing it. I'll also recommend a sway bar for the front. I paid about $20 for one at the pick a part and still need to install it but they're simple and improve handling. I'm running later Rallies (76 or so and up 4X4 wheels)wheels and a 225-70-15 front and a 265-70-15 rear. I replaced Ball joints, tie rod ends and tires when I did the swap but the ride is 100% or more improved. You'll probably also want to upgrade to power brakes and steering if you don't already have it. If you buy one make sure and get all the pulleys and brackets. The pulleys come in a few configurations and you may never match what you need if you have to piece it together. Make sure you get every pulley and bracket. I use McGaugheys spindles and springs and their brakes Kit (6 lug). It went on easy and works well. The last I checked that kit and the spindles were about $280 ea.(it's been a couple of years) Then tires and what ever replacement parts for the front suspension. Still under a grand with upgrades to Brakes, PS,PB, and drop. Power Steering was used from a later truck and the ratio is 3 1/2 to 1 while the original for the 68-72 is 4 1/2 to 1. The 68-72 PS feels too "mushy" to me but that's a personal preference. There are a lot of threads specific to each of these mods and I would suggest reading thru them to determine what works best for your application, skill level and budget. There are also write ups on using the Hydro boost PB system. Good luck and enjoy.

[68Stepbed]

Originally Posted by laketboy

Thanks Matt! Exactly the type of info I was looking for. BTW, beautiful 68 short bed step in your profile pic. Color is a shade lighter, but reminds me of my 02 Z06 Corvette Electron Blue. Back in the late 70's I had a 56 short bed step with wrap around glass, but didn't have the means to do a proper resto-mod project and sold her.

So, I assume your 68 step is dropped 2/4", correct? I think that is the look and ride height he's looking for. ALSO, what size wheels and tires are you running fore and aft? That would also help immensely!

Thanks again
Keith

In that photo, my truck is 4.5/6.75 drop. I'm currently sitting on a TCI front/rear suspension with coilovers for an equivalent to a 5/7 drop. I'm running 18x9.5 wheels with 285/40/18 tires on all four corners.

Here's the photo in my avatar.


This is how she sits, now.

[Mike C]

I would stay with a 17 or 18" rim. On my '69 short step I used the ECE 2 1/2" disc conversion spindles and 2" springs for 4 1/2" in the front. I wouldn't even consider keeping the drums FWIW if you want to use the truck...

My truck is a leaf spring truck so I flipped it with a DJM kit which dropped the truck just over 7". Total drop a 4 1/2" 7. I have 235 55 17 on 17x8 zero offset front and 275 55 17 on 17x9 zero offset. I converted to 5 lug with the disc kit and used a slightly wider 72 housing to make it work. That wheel/tire won't fit with the earlier axle. Once again, my opinion, 27" front and 29" rear tire heights work and look great.

I would start with the ECE 2 1/2" disc conversion spindles on your sons truck and a 5" spring in the rear. If not low enough you can add 1 or 2" lowering springs in the front and the rear you can go with a block. I think with just 6" total in rear you shouldn't have any issues with hauling things. I do with mine but it does hit the aftemarket bump stop pads the flip kit came with.

I the GR2 KYB shocks on mine. Rock Auto acquisition though. I used stock length fronts all the way around moving the upper mount in the rear to the unused second hole in the shock mount that comes on a leaf sprung truck.

[TCCGRIZ]

Subd thanks for the info guys

[laketboy]

Thanks for all the replies, now to process!