How do the cross sills sit? See pic inside....

[glock35ipsc]

Which way is the CORRECT way for the wood floor cross sills to sit on the frame? I have seen them both ways, but "B" seems to be the correct way, especially the way the splash pans mount. Anyone else?

Thanks!

[Richard Dobson]

That'll be "B"

[68speedalert]

Can't say for sure what is correct, but we put them in "B" way. Thought that was the way we took them out of afr72's shortstep.

I will look under my 68 longbed fleetside tonite.

[glock35ipsc]

Thanks guys!

[Palf70Step]

Yep....B is da way. Openeing down, so the cow poop and mud will fall out and not collect and cause rust. (Words of wisdom from an old Mississippi farm boy)

[ChevyDude]

Glock I have a brand new wood floor SWB here that is not assembled....I need this answer too! If I guess...it will turn out to be just the opposite, LOL!!!

[67ChevyRedneck]

No need to guess ChevyDude "b" is correct. My truck was bone stock never apart original and thats how they were and thats how they still are.

Think of it this way, that would be a lot of LONG bolts to bolt down a wood floor if "A" was correct, which it's not

[glock35ipsc]

I haven't ordered anything for the floor yet, I'll do that very last. I mainly wanted to know so I can cut the rear one correctly to set over the rear gas tank

[MAR-Ktech]

'B' is correct as all seem to agree. Steel floors have 'A' and wood floors have 'B'. Don't forget to install the mounting plate under the cross sill at each of the frame bolt points. These plates will keep the cross sill from spreading at the point where it sits on the frame. Also, note the cross sill just behind the wheels is shifted an inch or so from the position of the steel floor cross sill.

Sometimes we sell a reinforcing strip to use in place of a cross sill where the customer needs to clear something like a gas tank. It looks like a cross sill but is only about 1" tall. Just use something at the frame mount point to space up to the reinforcing strip.

Mar-Ktech

[glock35ipsc]

Straight from the horses mouth, thanks! A couple of questions:

1] Enlighten me on the "mounting plates". Are you refering to the factory mounting brackets rivited to the frame, or something else? As far as something to keep them from spreading, could I just weld a piece on either side of where the bolt passes through to keep it from spreading or closing up?

2] I have one of the smaller pieces. I will use that over the tank, thanks for the tip.

So, how many regular size and smaller cross sills do I really need? Do any of them run under the front or rear mounting holes of the wheel tubs? I've seen so many pictures and heard so many descriptions of how to install these floors, I have no earthly idea what goes where

[biglou55]

Bob i am with you on that one I have never dismantled one but i own two short steps that i got in tore down shape.I wish somebody who has done this would do A super good rebuild post that would be great just about now.or if there is one how do we find it.

[MAR-Ktech]

Originally Posted by glock35ipsc

1] Enlighten me on the "mounting plates". Are you refering to the factory mounting brackets rivited to the frame, or something else? As far as something to keep them from spreading, could I just weld a piece on either side of where the bolt passes through to keep it from spreading or closing up?


2] I have one of the smaller pieces. I will use that over the tank, thanks for the tip.


So, how many regular size and smaller cross sills do I really need? Do any of them run under the front or rear mounting holes of the wheel tubs? I've seen so many pictures and heard so many descriptions of how to install these floors, I have no earthly idea what goes where

1: The factory cross sills had a metal plate about 14 gage thickness welded to the bottom of the cross sills where the mounting bolts pass through. Mar-K cross sills come with these plates, but not welded. You could use any piece of metal there welded to the cross sills to keep them from spreading. Just don't make it real thick as that would change the height of the bed.

2: You will need one of the reinforcing strips that is 72 inches long under the front edge of the wheel tubs.

Short bed has 3 cross sills, one 72" reinforcing strip, and one 49-1/2" reinforcing strip. Long bed has same reinforcing strips and 5 cross sills. One of the cross sills does run under the rear edge of the wheel tub. With purchase of Mar-K parts, you will receive complete bed assembly instructions to answer many of your questions. This may help http://www.mar-k.com/67-72conv.pdf

Mar-Ktech

[glock35ipsc]

Excellent! Thank you very much for that info, it helps tremendously!

[ChevyDude]

Bob, I have a set of those plates, they are flat and then angled up on each side to prevent spreading I presume. I bought them from GMC Pauls.

Alex

[glock35ipsc]

OK, cool. I have plenty of 16ga here, I'll probably just cut some squares and TIG them to the inside of the sills with a 1" or so hole in the center.

[mbgmike]

Originally Posted by Palf70Step

Yep....B is da way. Openeing down, so the cow poop and mud will fall out and not collect and cause rust. (Words of wisdom from an old Mississippi farm boy)

We B correct

[ChevyDude]

Originally Posted by glock35ipsc

OK, cool. I have plenty of 16ga here, I'll probably just cut some squares and TIG them to the inside of the sills with a 1" or so hole in the center.

That will work!!! I need to learn how to weld!!!!!