Engine Crossmember Replacement

ORD is an option

link in green

[edit] sorry thats for 4x4, link below may be for 2wd but with extra parts you may not need. If anything give them a call.

https://www.offroaddesign.com/73-87-gm-4wd-ls-combo-kit.html

Thanks for all the info so far, everyone! Good stuff!

The truck is at my garage a few towns over which I really only get to on weekends. I'll see if I can get some pictures, but to my recollection, the majority of the back "wall" is rotted out. The whole front end hasn't collapsed yet, so I guess that's a good sign... Not planning on taking it down the road that way, obviously.

I do have a hefty welder and I'm pretty good with it, I just can't see the extent of the rot in the truck's current position. There's a possibility (being from the land of salt and disintegrating tail gates) it's too far gone, so I'm planning accordingly. If I can save it, I definitely will, but I'm preparing for worst case.

Now on an related note, if I'm going to lower the truck at some point, what are the limitations of the factory crossmember? I'd like to lower it to the point I won't need to C-notch the back. Exact amount is TBD, but just curious what the limit is with factory parts.

A good front crossmember down here is sw MS is a $100 - $150 part. Wonder what a bare crossmember weights? Shipping would probably be costly.

since you're good with a welder have you considered removing it and fixing it? Or do you think it's too far gone to cut and weld some fresh metal in?

legopnuematic said:

Man I sold a whole front frame section (complete suspension minus steering box) from the 85 I parted out a few years ago for like $150. Way less crusty too.

I guess inflation or supply and demand.

Click to expand...

No, whoever is trying to sell that is maybe trolling. Or waiting for the right person IMO.
But realistically it’s not that far fetched of a price if you think about it.
First, it’s a part that’s not made anymore and not a high demand. Very few “rusted out” and someone is actually trying to restore a truck in that bad of shape. If structural frame members are rotted out, the rest of the truck likely ain’t even close to being worth saving.
So mostly marketing to someone with a “nice” square that got in a wreck bad enough to bend the cradle. That happens very rarely given the relatively low numbers on the road and even lower numbers that are driven daily and at higher risk of a bad accident.
BUT if you need one you NEED it. Say an hour or 2 to remove it “carefully”. Another hour to pack it and take it for shipping. Probably $100 to ship. That’s worth a couple hundo right there if you’re a days drive from the good end of the salt belt AND need it. And the part is still “free.” Guys pay a couple 3 hundred for a schitty repop fender.
And those are dime a dozen, original or repop.

Check Craigslist in Phoenix. I regularly see complete frames and front suspensions very cheap. Lots of Suburbans get parted out here and lots of custom frames and front members swapped in for builds.

If you can't find one, let me know and I'll reach out to a couple of guys in the area.

NC595 said:

Thanks for all the info so far, everyone! Good stuff!

The truck is at my garage a few towns over which I really only get to on weekends. I'll see if I can get some pictures, but to my recollection, the majority of the back "wall" is rotted out. The whole front end hasn't collapsed yet, so I guess that's a good sign... Not planning on taking it down the road that way, obviously.

I do have a hefty welder and I'm pretty good with it, I just can't see the extent of the rot in the truck's current position. There's a possibility (being from the land of salt and disintegrating tail gates) it's too far gone, so I'm planning accordingly. If I can save it, I definitely will, but I'm preparing for worst case.

Now on an related note, if I'm going to lower the truck at some point, what are the limitations of the factory crossmember? I'd like to lower it to the point I won't need to C-notch the back. Exact amount is TBD, but just curious what the limit is with factory parts.

Click to expand...

How low you can go depends on what you want to do with the truck and your budget. For example, QA1 makes a whole replacement front crossmember to go with their tubular front end with rack and pinion, you can go 8" up front with that setup. With a stock crossmember and stock control arms, 5" is kinda the reasonable limit. You can get 6" with tubular arms and some other tricks. Most guys are some combination of 4-6" up front and 5-8" in the back.

Some trucks can get away with ~4/6 or even 5/7 without a C-notch, my buddy's truck was 5/7 and he said he'd only slap the rails if he added his big cooler to the normal roadtrip stuff.



I like the peace of mind knowing I can load the truck up and not bottom out, especially cuz I travel with alot of tools on roadtrips, so my truck is notched. I regularly work the truck (sometimes more than it should be) and I roadtrip it all over the country (43k miles in 3.5yrs). I'm ~5.5/8 with stock arms up front, 2.5" spindles with stock springs trimmed a little at a time till I was happy. Rear is a flip kit, 2" shackle, shock relocators and helper bags. Belltech SP shocks all around and it rides great. I can't *quite* get the front end in spec but still get ~25k miles out of the tires, I just have a little too much camber for the highway running we do.



Top is 4.5/6, middle is same with rallies, bottom is 5.5/8

First of all, VERY nice truck. Almost exactly what I'm looking to get out of ride height, honestly.

I did look at QA1 but they're definitely a bit out of budget for the time being. Still, a good option!

A few minutes ago, I found a local '85 C20 crossmember on Marketplace. Is it the same as the C10? Definitely a 2WD (has the front suspension still attached). Would love more info on the interchangeability between model years too if anybody has some!

NC595 said:

First of all, VERY nice truck. Almost exactly what I'm looking to get out of ride height, honestly.

I did look at QA1 but they're definitely a bit out of budget for the time being. Still, a good option!

A few minutes ago, I found a local '85 C20 crossmember on Marketplace. Is it the same as the C10? Definitely a 2WD (has the front suspension still attached). Would love more info on the interchangeability between model years too if anybody has some!

Click to expand...

73 - 87 engine crossmembers for 2wd trucks are all the same. My 74 C20 engine crossmember is the same as in a friends 86 c10.

NC595 said:

First of all, VERY nice truck. Almost exactly what I'm looking to get out of ride height, honestly.

I did look at QA1 but they're definitely a bit out of budget for the time being. Still, a good option!

A few minutes ago, I found a local '85 C20 crossmember on Marketplace. Is it the same as the C10? Definitely a 2WD (has the front suspension still attached). Would love more info on the interchangeability between model years too if anybody has some!

Click to expand...

Thanks! It's been quite the project, it's got a 5.3/T56 combo now and I'll actually be removing the whole crossmember/front suspension setup over the winter to replace with a TCI Engineering setup haha.

I'm about 99.9% sure the cradle is the same for C20s as it is for C10s, just different control arms/spindles/brakes

I have one sitting next to my garage I’d let go cheap. It’s in south central pa.

I found a guy on Marketplace yesterday that's selling a whole front suspension with the crossmember (includes drop spindles that I already have), so I'll be picking that up this weekend.

Thanks for the information, everyone! The whole "parts interchange" thing is seemingly very easy, but not a lot of information is readily available except first hand experience, as far as what I'm seeing.

Thanks again!