transmission crossmember possible warped frame?

[Liltroy]

hey guys I need some help/ opinions please. I have a 74 stepside and just dropped the transmission(th400) to replace the front seal. when I was unbolting the crossmember it seems that the passenger side uses the factory bolt holes but the drivers side is about an inch back and has had new holes drilled. The tail of the trans seems to be centered between the frame rails so the only way I can see that this would be possible is if the frame was slightly tweaked on one side??? If I try to slide the crossmmber forward an inch on the drivers side to match the factory holes then the trans mount doesnt quit line up with the holes in the crossmember. Where can I take measurements to figure out if one side of my frame is pushed back(possible from a front end hit on one side) or if the frame is warped somehow? Any help would be appreciated.

[Irish_Alley]

going on a limb here but is the cross member straight?

[bd]

If the frame was pushed back appreciably on one side I think the rear axle would dog track.  Post pics of the crossmember attachment to both frame rails and the transmission mount you're using.

[Liltroy]

irish, im gonna take measurements but it doesnt LOOK crooked, thats why im confused.

bd, your right, i didnt think about that but it only seems to be about an inch difference. its raining now but ill take pics when i can.

thanks guys.

[Liltroy]

it wont let me post pics. keeps saying theyre over 256kb....duh! lol

[bd]

     Here is a link to the tech section on how to upload pics to the forum.
   
     http://forum.73-87chevytrucks.com/smforum/index.php?topic=6428.msg33936#msg33936
     
     You could always host them on a site like photo bucket and then use the image code tab (right above the smileys, all the way to the left, looks like a mono lisa).  I use fast stone image viewer on my windows lap top, it is a free download to edit pics and do a whole lot of stuff.  It is very easy to use also.

to help out

Just left click the IMG code it should automatically copy it

[Liltroy]

my fingers are on the factory holes on drivers side
trans mount
passenger side holes

[Liltroy]

that was alot to go through just to post three pics,lol

[mechanic58]

Just a guess here - but I'm going to guess none of the SWB pickups ever came from the factory with a TH400 installed. That being said, the frames may not have been drilled for the crossmember to be mounted in the TH400 position.

Just a guess.

[Liltroy]

yes this truck came factory with a 350 engine and a th400 trans. build sheet is in the glovebox.  Holes line up on passenger side but drivers side has new holes drilled an inch back.

[bd]

1" at the left frame rail should be ~1/2" at the trans mount.  How do the motor mounts look?

[Irish_Alley]

If I rember right the trans cross member fits snugly into the frame and if the frame was twisted the cross member won't fit and the bolt holes would be misaligned and the holes would have to be egged out for the bolts to fit

[Liltroy]

1" at the left frame rail should be ~1/2" at the trans mount.  How do the motor mounts look?

im sorry but im not sure what youre asking. the mounts dont look twisted or anything and look pretty solid. Ive been having to do work on my duaghter car this week but im going to take some measurements this weekend and see if i can figure this out.