73-75 under floor

[CharlieC]

I bought my '74 K5 while in college (after my '72 Jimmy threw itself on it's roof) and did some rust repairs on a college budget. After 35 years, it's time to do it right...

The pan I'll call it that covers the floor underneath (attached to the rockers and on up past the body mount) was very rusty and for some reason, I cut the whole thing out vs cutting only what was bad. Actually kept it for many years, but it hit the trash in a move somewhere.

Is that pan unique to 73-75 K5 given the 76+ floor change, was it the same in K10's and/or?

Here's my pax side.


Here's my driver side.



There are several other things in that picture being corrected, but I'll start with this.

Thanks
Charlie

 

[imiceman44]

I bought my '74 K5 while in college (after my '72 Jimmy threw itself on it's roof) and did some rust repairs on a college budget. After 35 years, it's time to do it right...

The pan I'll call it that covers the floor underneath (attached to the rockers and on up past the body mount) was very rusty and for some reason, I cut the whole thing out vs cutting only what was bad. Actually kept it for many years, but it hit the trash in a move somewhere.

Is that pan unique to 73-75 K5 given the 76+ floor change, was it the same in K10's and/or?

Here's my pax side.
View attachment 385899

Here's my driver side.

View attachment 385900

There are several other things in that picture being corrected, but I'll start with this.

Thanks
Charlie

The part you're missing is an important part of the structure on a full convertible and yes it's unique to 73-75.
You can build a custom piece or build a cage to get the same effect.
It stiffens the floor in that area to keep the Blazer from folding in half.

 

[CharlieC]

Thanks for the reply. I have the old Smittybilt front cage/rollbar installed, but the front floorboard connections needs an upgrade to actually work upside down, should I unfortunately find myself there.

Charlie

 

[mechted]

Roll Cage vs Rocker Box on '74 Blazer

Will a Roll Cage be sufficient enough to support the cab on a full vert blazer? or will the rocker boxes need to still be there. My new to me '74 Blazer is fairly rust free. But I just noticed the cab supports that ran above the rocker box and contain the body mount nut are pretty much rusted...

ck5.com

Recent thread where Bigb55 rebuilt this area with a lot of pictures to document. Also has some good reference links to several other people doing the same job.
Since your passenger side is intact, you have a pretty decent idea what you need to build.

 

[CharlieC]

Thanks for that reference! I really like the space frame that 4x4Blaze built, looks like something I can do. I see his roll bar tie in idea as well, very nice.

I do need to change the inner/outer rocker and put in a real cab floor support vs the one I made.

Thanks!
Charlie

 

[Bigb55]

The under floor support pieces are the same as the pickups.

You will need a body mount, a cab floor support (cut the back part off) and inner and outer rocker (pickup piece cut to fit works best) Then you will need to fab up and bend a sheet metal square that ties it all together at the body mount cab support transition area. Then install the new floor pan.

The 73-75 have an unique floor pan. The weather seal lip area towards the rear is slightly different.

If the rocker box is rotting. It's easy to repair with flat pieces of sheet metal cut to fit. If you have one that is intact to copy. It's nothing more then 14-16 gauge sheet metal welded into a box. Then attached to the firewall and right before the second body mount channel.

If you build a sub frame the cab support and body mount still needs to be there. Along with some structure for the rockers.