Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Rear is going to stay as leafs for now. Step notch with an axle flip & relocated spring hangers (since I have to do some frame repairs around the hanger area anyhow, might as well relocated them for some added drop). Goal is about 6" drop front, 7" drop rear.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

no turning back now lol

Attachment 2037223

Attachment 2037224

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

A bit more progress - welded in crossmembers across the step notch & boxed in the step notch

Attachment 2043099

Then onto some frame rust issues.....

Attachment 2043101

Attachment 2043103

Attachment 2043104

Basically it was the same on both sides, the passenger side wasn't rusted all the way through, but was pretty damn close, so it got the same treatment.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Since the truck is going to be static dropped on leafs for now, and the factory crossmember was trash (rusted through.....), I figured I'd relocate the front spring hangers to add to the drop.

Moving the front spring hangers up 3" gets a 1 1/2" drop, there will be drop shackles as well which lowers 1" & the flip kit

Attachment 2043105

The truck is going to get a raised bed floor anyhow, so the new crossmember being higher doesn't affect anything. (The crossmember is bolted in now, so if I need to make changes later on it won't be difficult)

Attachment 2043106

Attachment 2043107

Attachment 2043108

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Temporarily put back together to see an approximate height & to make it rollable to get to other projects again.

Still need to get new bushings for the leafs, install the drop shackles in the back & make new shock mounts, then tear it apart and paint the pieces before bolting it back up with new hardware. It's going to need some shims on the diff for pinion angle as well I'm sure, but that won't be until it has a driveline in it.

Attachment 2043109

Attachment 2043110

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Nice re-use of what it came with adjusted for the new stance.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

What does "pancaking" the front cross member do for lowering the front end of the truck?

Is the point to allow raising the mounting of the cross member and suspension relative to the frame/body?

Great build thread BTW!

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Correct.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Thanks - and yes, it is moving the suspension relative to the frame. I could have done a 3 1/2" frame Z instead of the 2" Z & 1 1/2" crossmember section, but that would virtually guarantee that I would need to move the trans tunnel etc. through the cab as the driveline would be raised substantially 3 1/2" (or I could re-lower the driveline, but that's another headache).

This way I get the same effect - the truck is lowered by 3 1/2" without touching the springs or spindles, but I shouldn't have to modify the transmission tunnel (though I'm targeting around 5 1/2"-6" of drop in the front, so the springs have been cut as well, but I won't be able to dial that in until I have the truck mostly assembled)

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

A bit more progress -

New shock mount on axle (2 1/4" longer than the stock ones)
Attachment 2048149
The rest of the axle is just a rattle can rebuild for now lol

Quick clean & rattle can on the frame
Attachment 2048150

Good old Belltech drop shocks...... Not the best, but OK and inexpensive
Attachment 2048151

And here's where it's at now - About an 8-8 1/2" drop using stock springs. It has an axle flip, relocated front spring hangers, drop shackles, extended shock mounts, step notch etc. Still need to work out what gas tank I'll end up using - that will require some more fab work for sure.

Attachment 2048152Attachment 2048153

About $400 into the rear suspension & frame fab, so pretty cheap drop overall. Not real pretty like a 4-link setup, but this truck is just being built on the cheap, so it is what it is.

Next up - cab rust.....

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

The kool thing is you can always get a 'bolt-in' 4-bar kit @ a later date and bolt it in. Add new upper shock mounts for some coil-overs. Little if much extra fab.

Well done from a budget perspective!

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Yup, that's the plan. 4-link eventually, trying to keep everything so that I'll be able to do that without much pain down the road

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Looks great!

Are those rear shocks the same length as stock or are they shorter?

For the flip, did you use a kit with the U brackets or did you weld in real spring perches?

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Thanks
They are shorter shocks - Belltech Nitro Drop 2 shocks for a 4-6" drop. I built the extended axle end mounts since it's at about an 8" drop, also helps a bit with the shock angle.

For the flip - it's just a U-bracket kit from Western Chassis. When I get to setting pinion angle I may weld in new spring perches, but that won't be until there is an engine/trans dropped in.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

67-72 Blazer tank? I suggest the 67-72 over the 73-87 for the smaller footprint. Technically you have the room for the 73-87 Blazer/Burb tank but they take up frame space all the way up to the rear-end housing. The 67-72 Blazer tank doesn't eat up that much frame length.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Haven't really decided on the tank yet, but it will be between the framerails in the back & needs to have an in-tank pump (it'll be EFI, don't want an external pump). I'll have to look at the 67-72 Blazer tanks. I've got a 90 K5 I can use for comparison on tank size as well.

Wifey's daily that I built a couple of years ago -
Attachment 2048345

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

What I know....
The Square Blazer tanks:
*Def fit.
*Came w/OE in-tank pumps for the final year models.
*They have a big foot-print.

67-72 Blazer tank:
*Fit between the rails.
*Might be available aftermarket w/an OE style in-tank pump set-up.
*Smaller foot-print but possibly slightly lower vs. the Square-body model.

1st GEN f-body rear tank:
*They fit between the rails after some trimming.
*Available aftermarket w/OE style in-tank pumps.
*Smaller foot-print & possibly as shallow as the Square-body tanks.

Just some ideas as I can tell you're no stranger to this.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Thanks - If I had a brain I would have done a quick test fit with the K5 tank when I had it out to replace the fuel pump a month ago lol (I kind of figured it would be too big). I'm definitely not sure on what option I'll go with, I'll probably look at it after I get through the cab rust repairs..... The first gen F-Body one might be a decent option, I think I can get one from a friend for a test fit.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

I just bought a 78 SWB, and I'm toying with the idea of something similar in the front. What does the clearance look like at the core support with the Z? Specifically the support/radiator/efan/frame/steering box interface. This truck will be static, and I'm wondering, how much is too much? Half ton springs with a coil cut, 2 1/2 drop spindles, a pancake and a z, I wonder what that adds up to in the real world? Because at some point, the really low bagged guys are using the bags to get the frame off the ground, not so much "suspend" the truck, if you get my drift. I guess the question is, how much is too much, with a static drop. I dig your work. I'm considering the 49-52 tank for my behind the axle tank.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

It takes 4" to get over large speed-bumps, turn-lane dividers (City Tiddys), & most concrete curbs. Most high-end rod-shops use that 4" marker as a max for static clearance under the vehicle for trouble-free driving.

My dually has 4-5" @ the rails/front x-member & I only worry about high-centering which happens a lot more when it's a 20' chassis (CC LWB).

Measure where you are now & use that 4" number as a benchmark for reference.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

Back when I used to run really dropped trucks, We called it "beer can " clearance. If a Bud Light can laid on its side just touched the crossmember, that was about right. Of course, now we're discussing moving the crossmember up. So, you figure 4 ish with the standard parts, 5 1/2 with the crossmember, and a 2" z, you're at 7 1/2- 8, give or take. Just wondering where the line might be. Right now I'm a roller at stock height. This truck is getting completely stripped, just trying to figure how much I want to do while it's apart.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

I'm just shooting for a 5 1/2"-6" front drop and an 8" rear drop for now. I'll see what it all looks like when it is put back together and adjust from there. I know I'm safe at the 6/8 range.

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

That's my bet as well. A 6/8 drop is a great profile stance for the Squares but not enough ground clearance w/a typical static drop. Once you factor in the sectioned x-member & mild 'Z' mods you did that's an extra 3.5" of clearance vs the typical spindle/spring combo. Add some 2.5" spindles & you're @ your desired 6" front drop w/a stock length coil/shock combo for a very decent ride quality.

The way you re-engineered the rear mounting points gives you the easy flip kit drop number & then some but w/better shock angles. There is bed space sacrificed this way but even w/a typical 6-7" of rear static drop via flip kit you'd likely be banging on the c-notches & tapping the bed floor occasionally.

Eliminating that interference = better ride quality. I would gladly sacrifice 3-4" of cargo space for a no-interference ride quality.

Is this going to be a stepper or fleet?

Re: #corona10truck - 77 C-10, pancaked crossmember - z'd frame etc etc etc
 

I think you're correct on the suspension situation, just trying to keep it somewhat comfortable, it's not going to set the world on fire for handling or performance, just a lowish truck static dropped.

The rear axle right now is sitting more or less at the same level as the old bumpstop without a box on the truck, or fuel tank etc etc, so even with a c-notch it probably would have hammered it occasionally, and I may end up putting a 4-link & air on this thing down the road, so figured I might as well step it (plus I had the 3/16" steel anyhow, so it was just a matter of cutting it out and welding it up - trying to keep this as low-buck as possible - I'm only into this thing for about $3200 Canadian right now)

I've got a fleetside box that's in decent condition, so that's going to go on it (needs a bit of repair, but not too bad). I'm not to concerned about losing a bit of cargo area on this truck, it probably won't end up with anything in the bed anyhow, but I'm sure someone will be annoyed when I cut up the mint box floor lol.