Cross sills questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

beardo73 · 03-01-2015, 05:05 PM

So I am about to replace the floor in the 1972 K5 Blazer. When I was looking down there, the cross sills are either rusted so bad they disappeared-- or the previous owner did not put them back on when he attempted his resto...

I'm not having much luck finding anything Blazer/Jimmy specific on reproduction parts.. So I guess my question is are there any made for SWB trucks that would work? How many cross sills do I need under there? Any personal experiences with this issue? I'll even take dimensions of anyone has them! Worst comes to worst I'll end up going to the fab shop and have them help me out...

Thanks for any and all help!

Musclerodz · 03-01-2015, 06:46 PM

I know the rear wheelhouse cross sill is 2" shorter, but you could make it work by just notching the cross sill from the body mounts in. The intermediate cross sill between the tubs is the same. I know about those as I just changed them. I would have to compare the others to be sure on those.

69-72 · 03-01-2015, 07:49 PM

This might help

grillzy · 03-01-2015, 08:01 PM

That is one great picture!

beardo73 · 03-02-2015, 11:33 AM

That is a fantastic picture! Thank you for posting that!

Wouldn't happen to have any dimensions off of that would ya?

Thanks again!

69-72 · 03-02-2015, 10:47 PM

The two sills on either side of the wheel well are like this. The flanges not are ~1" on one side and ~1/2" on the other. The short cross sill in the middle is the same size but the flanges are equal ~1/2" each side.

These sills are the same as on a pickup. Probably would be easiest and best to get some bent up, I have had that done before.

If you can find a decent steel bed floor from a pickup you can use that as a replacement. Thats what I did, took a long bed floor and sectioned the back half and welded the Blazer specific front on it. You can use the crossmembers too, don't even need to take them off.

69-72 · 03-02-2015, 10:56 PM

Bonus pics

beardo73 · 03-03-2015, 09:45 AM

That is great! Thanks for the pics and info.

I didn't even think about trying to swap in a decent long bed. That might be the easiest way to go.. Time to poke around and see what I can find!

Thank you again for all the help!

69-72 · 03-03-2015, 09:59 AM

If you find a short bed floor you wouldn't need to do the rear section.

03-01-2015, 05:05 PM	#1
beardo73 Registered User Join Date: Dec 2014 Location: Slippery Rock, PA Posts: 25	Cross sills questions So I am about to replace the floor in the 1972 K5 Blazer. When I was looking down there, the cross sills are either rusted so bad they disappeared-- or the previous owner did not put them back on when he attempted his resto... I'm not having much luck finding anything Blazer/Jimmy specific on reproduction parts.. So I guess my question is are there any made for SWB trucks that would work? How many cross sills do I need under there? Any personal experiences with this issue? I'll even take dimensions of anyone has them! Worst comes to worst I'll end up going to the fab shop and have them help me out... Thanks for any and all help! __________________ 1972 K5 Blazer in progress!

03-01-2015, 06:46 PM	#2
Musclerodz Senior Member Join Date: Aug 2005 Location: OKC, OK Posts: 2,364	Re: Cross sills questions I know the rear wheelhouse cross sill is 2" shorter, but you could make it work by just notching the cross sill from the body mounts in. The intermediate cross sill between the tubs is the same. I know about those as I just changed them. I would have to compare the others to be sure on those. __________________ Mike Redpath

03-01-2015, 07:49 PM	#3
69-72 Registered User Join Date: May 2008 Location: 204 Posts: 903	Re: Cross sills questions This might help __________________ 1969 Chevy Custom Camper 3/4 ton Rust free survivor 1972 Chevy Blazer CST 4x4 Almost Rust free survivor 1972 GMC Jimmy 2wd Undergoing surgery

03-01-2015, 08:01 PM	#4
grillzy Registered User Join Date: Jan 2014 Location: belleville ontario Posts: 354	Re: Cross sills questions That is one great picture!

03-02-2015, 11:33 AM	#5
beardo73 Registered User Join Date: Dec 2014 Location: Slippery Rock, PA Posts: 25	Re: Cross sills questions That is a fantastic picture! Thank you for posting that! Wouldn't happen to have any dimensions off of that would ya? Thanks again! __________________ 1972 K5 Blazer in progress!

03-02-2015, 10:47 PM	#6
69-72 Registered User Join Date: May 2008 Location: 204 Posts: 903	Re: Cross sills questions The two sills on either side of the wheel well are like this. The flanges not are ~1" on one side and ~1/2" on the other. The short cross sill in the middle is the same size but the flanges are equal ~1/2" each side. These sills are the same as on a pickup. Probably would be easiest and best to get some bent up, I have had that done before. If you can find a decent steel bed floor from a pickup you can use that as a replacement. Thats what I did, took a long bed floor and sectioned the back half and welded the Blazer specific front on it. You can use the crossmembers too, don't even need to take them off. Attached Images __________________ 1969 Chevy Custom Camper 3/4 ton Rust free survivor 1972 Chevy Blazer CST 4x4 Almost Rust free survivor 1972 GMC Jimmy 2wd Undergoing surgery Last edited by 69-72; 03-02-2015 at 11:00 PM.

03-02-2015, 10:56 PM	#7
69-72 Registered User Join Date: May 2008 Location: 204 Posts: 903	Re: Cross sills questions Bonus pics __________________ 1969 Chevy Custom Camper 3/4 ton Rust free survivor 1972 Chevy Blazer CST 4x4 Almost Rust free survivor 1972 GMC Jimmy 2wd Undergoing surgery

03-03-2015, 09:45 AM	#8
beardo73 Registered User Join Date: Dec 2014 Location: Slippery Rock, PA Posts: 25	Re: Cross sills questions That is great! Thanks for the pics and info. I didn't even think about trying to swap in a decent long bed. That might be the easiest way to go.. Time to poke around and see what I can find! Thank you again for all the help! __________________ 1972 K5 Blazer in progress!

03-03-2015, 09:59 AM	#9
69-72 Registered User Join Date: May 2008 Location: 204 Posts: 903	Re: Cross sills questions If you find a short bed floor you wouldn't need to do the rear section. __________________ 1969 Chevy Custom Camper 3/4 ton Rust free survivor 1972 Chevy Blazer CST 4x4 Almost Rust free survivor 1972 GMC Jimmy 2wd Undergoing surgery

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