The Stovebolt Site Forums The Shop Area The HiPo Shop 55-56 Core Support Location - Different than 58-59

I am in the middle of installing a '79 Monte Carlo clip onto the front of what I thought was a '55-'57 3100 bare frame. The guy I bought if from said it was a '56 frame. I found out later that the frame turned out to be a '58 frame, and the overall length of the '58 frame was a little over 2" longer than the dimension of a '56 frame. Once I researched into my '55-59 assembly manual, I was able to locate the '55-57 frame specs, but didn't find any '58-59 frame dimensions. The '55-57 frame has an overall length of 178". This is shown on section 2 page 24 of the assembly manual. My '58 frame, before I cut it was 180-1/4" overall. I do know that the wheelbase is 114", common to all '55-59 Task Force trucks. I have gathered info on various forums that state the extra length of the frame siderails is at the very front of the frame, and everything in between is exactly the same. I have recently found out that the core support location is also different. The '55-57 trucks have a different core support than the '58-59 trucks, and I knew that. What I didn't know was that the '58 core support brackets that are riveted on the top of the frame rails are located 1" further towards the front of the truck. I initially made a jig to locate the front core support of the truck, so that after I spliced the Monte clip onto the frame, I could also attach the core support and front bumper frame ends off of the original frame using my jig. This jig bolts to the frame, and also bolts into the front core support mounts themselves. I have vertified that the '58-59 core support center line is 1" further towards the front of the truck, than the '55-57 frames. After measuring everything a bunch of times before I cut the original frame to graft on my Monte clip, I found this out. The factory assembly manual has the frame specs in section 2, sheet 24. A bunch of the dimensions refernce the "Front of Dash" line. The center of the "Radiator Bracket" for the '55-57 is 33.76" from the Front of Dash reference line. My jig that I made BEFORE I found out that I had a '58-59 frame located the front core support exactly 34-3/4" from the Front of Dash line. Pretty much 1" further forward than the '55-57 frame spec. So I adjusted my jig back 1" to then get everything back into alignment. I am wanting to document this to hopefully verify that the dimensions are different on the core support bracket locations from the '55-57 and '58-59 trucks. I know now that the frames are not exactly the same, yet with a few modifications, they can be interchanged. One other note I have found once I started researching frames. The radiator support brackets riveted on the frames have two different styles. One bracket has a cage nut and the bolt goes down through the core support and into the frame bracket. It allows for maybe 1/4" adjustment. The other style has a "T" slot and uses a carriage bolt setup. This design allows the head of the carriage bolt to slide into the slot on the frame bracket for adjustment, with the bolt facing up and a nut on top to secure the core support. I don't know what year diffences there are on these types of core support brackets. If anyone has any info, I would like to know. Thanks!

in my experience with a number of 55-59 trucks, the only difference in the frames is the 58/9 is about 2" longer to accomodate the splash pan behind the bumper .... marked here on the 58 frame that I used to assemble a 56 cab and 57 front end, using rad mounts in the original position from the 58 frame - fit fine .... I believe the carriage bolt type hardware was the earliest [55]

where you may be finding differences is in the V8/6cyl mountings - the V8 moved the core support toward the cab, back to the place where there's a triangular flat on the inner with a spot welded reinforcement on the 5-7 ... the assembly manual really only applies to 55, as they didn't print later editions incorporating running changes

Bill

Bill,

Thanks for the information on the issue. I have another "original" assembled truck that is an early '55 2nd series 3100 that has the carriage bolt slotted core support brackets. It is a 6 cylinder and is mostly assembled, although not untouched. The frame # and cab # match, so I know it is definitely a 55 truck. This extra frame I bought I was told was a '56, yet found out later it was a '58. I simply bought it so I could modify it with an IFS Monte clip, without having to completely tear apart my original '55 truck. The '58 frame did have the original V-8 motor mounts, and what I am finding out is that this frame is the one that has the core support brackets 1" further out from the cab, than the '55 location. I took the front end apart on my original truck and removed the core support to verify dimensions. It does coincide with the Assembly manual as far as the distance from "Front of Dash" line to the centerline of the core support bolts. I am totally new at this, but I had been told that the radiator mounting tabs that run vertical and attach the radiator to the core support themselves were a different offset between V-8 and the 6 cylinder, moving just the radiator up or back towards the engine (I don't know which engine has the radiator closer or further away), but that the core support was the same for both. I may be wrong, but wouldn't the core support have to be located the same distance away from the cab if the core support is not different between the V-8 and the 6 cylinder? The inner fenders and front fenders themselves have to fit the same dimension, so the distance has to be the same I would think. Your truck looks great by the way! What do you think?

"I had been told the radiator mounting tabs that run vertical and attach the radiator to the core support themselves were a different offset between V-8 and the 6 cylinder"

no - the 55-59 rads are all identical, an "H-55" will fit any year, 6cyl or 8

for the 55-57, note assy man sect 13 sheet 5-14 for 6 cyl - RPO 408 sheet 4-5 for V8 ... the small brackets that the core support bolts to on the frame are moved back for the V8 [riveted on 6cyl trucks, bolted on V8 trucks] - if I remember right, the front hole of the bracket moves to the back hole on the frame, about 4" - then there's some special sheet metal that fills in front of the rad as shown in the RPO

I've never seen a 58/9 V8 that I'm sure was factory, but AFAIK the mount points for them stayed the same 6 or 8, and they had a fan shroud for the V8

all TF 6's mounted the same in relation to the cab, and the rad was about 3/4" from the fan - the 265/283 is 4-5" shorter than the 235, so 1" forward difference isn't understandable, the shroud was only about 3"

I'll measure someplace on my 58 frame tomorrow and let ya know

Bill

Bill,

Thanks for the update and valuable information. You have had alot more experience with these trucks than I have, and I found your pictures interesting. I learn more every day on these great trucks! So if I understand this correctly, this is what I have gathered so far:

All 55-59 TF 3100 trucks have the exact same location of the core support brackets on the frame rails. If they are riveted, they were a 6 cylinder, and if they were bolted (factory) they were V-8.

If the core support brackets were bolted (RPO 408 sheet 5 of the assembly manual)they were closer to the cab approximately 4". The core support ITSELF is actually recessed further back into the grill opening, and the difference of the recess is made up with sheet metal parts around the perimeter of the core support. This would allow inner fenders and front fenders to attach at the same distance from the cab, yet they would attach to the filler panels out in FRONT of the core support? I think I am understanding this better.

On other thing. Again I am a newbie at trying to figure this stuff out, but the "56 V-8 frame" that I bought and later found out was a '58-59, must NOT be a V-8 frame. The core support brackets are factory Riveted on, meaning it must have been a 6 cylinder frame. Like I explained before, I made a jig that bolted to the frame with cross braces using factory holes. I made it stiff enough and included the front core support bracket locations (it actually bolts to them) so that when I cut the front of the frame off to install my Monte Carlo clip, I could bolt this jig back on, and the front brace that bolts to the front core support brackets would essentually be hanging out front to locate the exact location of the core support brackets. I would then cut off the front frame rails of the original truck frame and graft them on in front of the Monte Carlo clip. My jig has numberous measurements that I verified with a laser and marked and labeled. I checked and double and triple checked before I cut anything! I have what I feel is the exact "Front of Dash" line located on my frame and jig. From that line (Section 2 Sheet 24 frame sheet)it shows 33.76" to the centerline of the radiator bracket. My jig is at 34-3/4" exactly. That is what I don't understand. I will wait and see what you get on your measurement. Thanks again for your help.
Ed

Bill,

I just went out to get a reference on my mostly complete 55. I got it as someone elses incomplete project, so it was never totally assembled. It did have the hood and core support and inner fenders loosely attached with a few bolts, but no front fenders were included. This is why I guess I am having a hard time visualizing how the fenders to core support area lines up. The engine and hood and radiator (hanging) are still in place, as well as the cab and bed. This is the truck that has an original 6 cylinder. It does have riveted core support brackets, but they are slotted. I removed the core support by loosening the nuts on the carriage bolts, and slid the core support forward about 2" and it came out. I did get some dimensions off the truck, referencing the 1/2" hole above the front axle, located on top of the framerails. I get from the centerline of the 1/2" reference hole to the centermost point of the slot on the core support bracket 17-1/2". This verifies the dimension in the assembly manual. In the assembly manual, it shows 33.76" from the "Front of Dash" line to centerline of the radiator bracket. It is hard to reference a "Front of Dash" point on an actual truck. I took the 16-1/4" to the centerline of the 1/2" reference hole to the "Front of Dash" line and subtracted that from the 33-3/4" (33.76)+-1/16". That should be almost exactly 17-1/2" difference, or the distance from the 1/2" reference hole to the centerline of the radiator bracket.

Something else I picked up on the assembly manual is that the front axle centerline is actually behind the 1/2" reference hole located on top of the frame. They show a distance of 16-1/4" to the reference hole from the "Front of Dash" line, yet the front axle centerline is 15-3/4" from the "Front of Dash" line, a difference of 1/2". The front axle is 1/2" behind that reference hole. On my truck, the straight axle looks to be almost in line with the front brake lines that come out of the side of the frame rails. Anyway, more interesting info that I have found.

My other frame that I am modifiying is at a different location at a shop, so I can't get up there today with everything going on. I also thought about undoing the front clip (it's not welded on yet, just fitted together) and again checking a few things. I still can't deny that my jig was made and installed on the '58 frame without any thing removed or altered in any way. I am really unsure of the 1" discrepancy in the location of the core support.

I looked at the 58 - a hard freeze at the moment makes it difficult to do much, especially crawling under!

here's one reference - as everything fits the same on all 55-57 1/2T's, the distance from the back rivet of the core support bracket to the front rivet of the 1st cross member should be the same on all .... the only early frame [57] I have now is hours away at a friends

I found a pic of a 5-7 w/ V8 - the distance the rad is moved back is shown by the flat sheet metal piece just in front of the rad tank - that position will be evident as the area where there's a 3-holed reinforcement spot welded on the outside of your 55 inners .... and here's one of my 58 shroud, making up about the same distance

yes, I'd forget about that 'front of dash' measure, could be off from variations in cab mounts or other things

Bill

Bill,

I went out and confirmed that my radiator support bracket was 3-1/2" away from the front crossmember rivet to the rear radiator bracket rivet, the exact same dimension that you show in your picture. This is on my '55 truck that is mostly complete. I will know tomorrow where I am at on my '58 frame with the Monte front clip. It is at a different location at the school where I work. I need to get some pictures posted of my situation, and will try to work on that tonight still. My radiator support bracket is attached with rivets exactly 5" apart on center. The core support was attached at the center of the adjustment, or at 2-1/2" between the rivets of the radiator support brackets. You could see the wear and rub marks made by the rubber grommet that were between the core support and radiator support brackets. Thanks again for your help.
Ed

Ed - if the pics you have on your Opera page are the 58 frame [V8 mounts, must be], the rad mt bracket looks to be in the right position

I didn't notice the link before cuz you didn't finish it with the [/url] on the end - better link is this, in place of what you have now

Bill

Bill,

I tried to post some pics on the same location that you did for yours, but haven't got it figured out yet. My pics are posted at the site, but don't know how to get it set up like yours, where you just click on the blue description. I need more experience with that, I haven't done the link thing before. I will try and get that updated.

I did check my '58 frame today, and it does have the radiator brackets located 3-1/2" CL of rivet to CL of rivet like you referenced before. I don't know what the factory V-8 mounts look like for the '58 (the guy told me the mounts were for V-8), but if they are, why are the radiator support brackets riveted on, wouldn't they be bolted on from the factory? I will try to put some more pictures on the opera site under a different album that show details of what I am talking about.

Here are some discrepancies I found today. My '58 radiator support brackets are located 3-1/2" from the main crossmember, but the bracket attaching rivets are 6" OC, rather than the 5" OC of my '55.

My '58 core support brackets are 18-1/2" CL to CL to 1/2" reference holes located on top of the frame. My '55 core support brackets are 17-1/2" CL to CL to the 1/2" reference hole. There is the 1" difference I am coming up with. I am lost as to what to set the core support dimension to. If anyone has there frames available to measure, it would be great to set what everyone else is coming up with.

no, by 58 the 6cyl and V8 rad was always riveted in the same location, which is the position that the 6cyl rad was in 55-7 - that's why I'm sure the 58 frame rad location will be correct for putting on your earlier front - go with it for your mods, using reference points on the frame for getting the mounts properly positioned on the clip .... just need to remember the front horns are a couple inches too long for bumper mounting

the factory V8 mounts are the brackets riveted to the front cross member holding the pegs with rubber donuts on, which bolted to the front of the 283 - you won't be using them, but worth salvaging for someone

the other thing you'll want to consider is where the hand brake cross shaft is riveted to the driver side rail (already removed) - might want that later for setting up the original style e-brake

for the link in your sig line, you need to remove that "/url" from the end of the address (change to /albums/) and then add: [/url] after the word Pics ... like so
[ url=http://www.my.opera.com/Oleblue55/albums/]1955 Truck Progress Pics[/url ]
[[remove spaces beginning and end and it'll be "live"]]

Bill

Bill,

I was able to upload a few more pics of my dimensions I am getting. They are on album 2. Thanks for the heads up on my URL stuff! I am trying to get a clue on getting the computer forum stuff down.

I will get some pictures tomorrow on the original '55 on the radiator support bracket dimension.

I know there is a difference on the 55-57 and 58-59 radiator supports, because the parts suppliers list them seperately, but I don't know what that difference is,so maybe there is something built into them that may explain something?

I do have the emergency brake cable brackets and hardware from the frame and have saved them to use later.

Thanks, Ed