55.2-59 Radiator support swap.

[dsraven]

those little angle brackets on each side, that retain the crossbar with the hood latch attached, would be easy to fab. I have pics of the dimensions etc if needed. the bar behind the upper grill surround is a separate piece from the other cross bar with the latch.

[dsraven]

what did you say your frame is from?

[jmlloar]

Sorry been into a hundred other things.
The frame I am using is a 1980 C20 2wd with heavy-duty brakes.

What I have found out so far. The 55, 56, and 57 GMC fenders are the same as the 57 chevy fenders. The lower valance panel from 55 chevy is not going to work. The GMC valance is a smooth panel that is actually part of the grill opening, where the chevy valance is hidden by the grill.. The Chevy hood latch panel appears to fit perfectly with the GMC hood and hood latch. So it appears that I need the filler panel that holds the center mustache to make the GMC parts fit the chevy hood latch panel. The rest of the stuff I need is mostly universal between chevy and GMC.

So my next goal is to get fenders, inner fenders, and the few GMC pieces that I need.

[mr48chev]

With it cobbled onto that later model frame you are going to have to do a lot of cutting and fitting before all is said and done.

I don't know what radiator setup that 57 GMC that I had out here for years had as the truck had a 283 in it with a power glide. It was a total rust bucket though.

Looking at the radiators there are probably some very noticeable differences in the top panel over the core supports. That and you may be seriously modifying that cross piece under the radiator for clearance.

[jmlloar]

All that part is done. Rad support is installed, radiator is mounted to support. Hood is on it and everything looks good. All I need to do is figure out which pieces I need to mount the GMC center mustache to the chevy hood latch panel. And since the Canadian GMC came that way from the factory I just need to know what pieces they used.
Only cutting I will have to do will be modifying the drivers side inner fender to clear the steering shaft.

[jmlloar]

Test fit so far

[dsraven]

I would say hange the fenders, with the front inner fender extensions attached, and bolt them up to the rad support. then, the lower fender parts at the front are held together and spaced apart correctly with a simple flat sheet metal part, with returned edges for strength, which has small angle brackets attached on the rear top side that bolt to the front of the rad support and each end of that sheet also bolt to the bottom of the front fenders.
attached is a of pic of my Canadian 57 GMC which is sitting on a 2004 envoy frame. the rad support is one that I built to fit my needs so disregard that part as well as the total mess under the hood. the front bumper also has a sheet metal part attached behind the bumperette's that hangs over top of that lower fender connector part but it is not attached in the pic. there are a couple of angle brackets attached to the inner fender extensions, further up, that the crossbar for the hood latch attaches to on both sides.
if you want some pics of something specific let me know with a pm that includes your email address and exactly what you are looking for.
hope that helps.

[dsraven]

your truck looks good, sitting a lot taller than mine for sure.

[jmlloar]

I dont mind it being a little bit taller than stock. It will see it's fair share of dirt roads. Going with 235/80-16 tires to keep the tall skinny look of the 7.50-16 but using radials. So they should help fill in the fender gap.
It should squat a bit more once I start adding the weight back into it. right now its not much more than a complete chassis, engine, tranny, and a bare cab. A lot of stuff not on it will add a considerable amount of weight.

[jmlloar]

Originally Posted by dsraven

your truck looks good, sitting a lot taller than mine for sure.

I dont think its much taller than it was on its original frame.

[jmlloar]

What I need (guessing) is just the top cross bar that the center piece of the mustache is attached to. Then I can figure out exactly how to attach it to the chevy latch panel. It might bolt right up, or the Canadian model might use a different one than the us model. At this point I don't know what I need to do.

[jmlloar]

What I need (guessing) is just the top cross bar that the center piece of the mustache is attached to. Then I can figure out exactly how to attach it to the chevy latch panel. It might bolt right up, or the Canadian model might use a different one than the us model. At this point I don't know what I need to do. I have the GMC latch panel but it's not in very good condition.

[mr48chev]

Originally Posted by dsraven

I would say hange the fenders, with the front inner fender extensions attached, and bolt them up to the rad support. then, the lower fender parts at the front are held together and spaced apart correctly with a simple flat sheet metal part, with returned edges for strength, which has small angle brackets attached on the rear top side that bolt to the front of the rad support and each end of that sheet also bolt to the bottom of the front fenders.
attached is a of pic of my Canadian 57 GMC which is sitting on a 2004 envoy frame. the rad support is one that I built to fit my needs so disregard that part as well as the total mess under the hood. the front bumper also has a sheet metal part attached behind the bumperette's that hangs over top of that lower fender connector part but it is not attached in the pic. there are a couple of angle brackets attached to the inner fender extensions, further up, that the crossbar for the hood latch attaches to on both sides.
if you want some pics of something specific let me know with a pm that includes your email address and exactly what you are looking for.
hope that helps.

He nailed it spot on, you have to put the fenders on to be able to make sure that they will even fit and then fit the rest up to the fenders as you may have to raise the front of the cab to get the fenders and hood to fit right. That is
unless you have already done that part and didn't mention it. Anytime you do a subframe swap or frame swap you spend more time fitting the nose back on than with the rest of the swap.

[jmlloar]

The mechanical side and bodywork side of the project is not something that is new to me. Only problems that I am having is not having enough info on what I am missing parts wise, and mix matching parts from different years and models to make what I have in my mind as a finished product. And of course that has changed as I move forward and have to modify my design for stuff that wont work together and stuff that works better than my original plan.

It gets expensive guessing at what parts to order just to find out after spending a bunch of money I have to abandon that idea to move ahead with a complete different plan.
Thats how I ended up with the frame swap after dumping a ton of cash into my original 55 frame. and that led to the chevy rad support

[jmlloar]

Also I am using ez swap mounts and they have a ton of adjustment built in. and if need be I can add shims to the cab mounts to raise or lower the front sheetmetal.

[mr48chev]

Originally Posted by jmlloar

Also I am using ez swap mounts and they have a ton of adjustment built in. and if need be I can add shims to the cab mounts to raise or lower the front sheetmetal.

That should help a lot for having it squared up. I primarily remember a couple of TF on late chassis around here that were hacked up messes. No kits and no plans but both were on 4x4 chassis back in the 90's when swapping an early truck body on a mid 70's 4x4 chassis was the hot lick.

[jmlloar]

Yea, I remember that time. Everyone was putting anything on a chevy blazer frame. I remember chevelle and corvette 4x4's and beetles on Jeep frames bet most of that stuff has been scrapped by now

[mr48chev]

There was 69 El Camino on a shortened 3/4 ton chassis in this area in that time frame that I would have liked to get my hands on. As you said, most of those including that one seem to have disappeared.

[jmlloar]

There was a mid 70's firebird on a blazer frame for sale near here last year

[mr48chev]

Originally Posted by jmlloar

There was a mid 70's firebird on a blazer frame for sale near here last year

I've seen a lot of different bodies stuck on 73/87 4x4 chassis. In the late 90's you could by a good running 3/4 ton with a beat up or rusted out body pretty cheap around here and the neighbor kid stuck a 68 long bed cab and body on one making a real nice truck.

There was one with a Lincoln sedan body sitting on it for sale about 50 miles from me about that time that was pretty cool but a bit crude in the install.

[NWA58]

Originally Posted by jmlloar

the support on the gmc looks similar to the 47 to 55.1 but all the little stuff is definitely different.
Some of my gmc only stuff is shot, so I will just go with the chevy support.
The chevy radiator is half the price of the gmc one.
and to use the gmc one I would have to remove the 1980 front cross brace and fab a custom one up. since the chevy support sits on top of frame rails it clears fine with no mods.

Radiator support is mounted now so I just need a few of the other stuff.

Mine is a 58 but it came new from GMC with the V8 option and it used the same rad support as Chevy. When TCI made my chassis from a 1957 jig they had used before, they put an extra/unnecessary crossmember that dips down for the GMC 6 and taller radiator. My original V8 rad support is shown over the lower crossmember same as yours. No harm in extra strength. Yes, fenders are the same except for emblem holes. Upon disassembly I found a Chevy fender on my left side with the Chevy holes filled and GMC holes drilled.

[jmlloar]

The 58/59 already uses mostly chevy parts including the chevy radiator support and chevy hood. (sounds like they used a 55 to 57 gmc front crossmember on yours, the 58 59 frame would also be slightly longer where the bumper attached)

My problem is: the 55 to 57 usa made gmc uses gmc only front end components (only the fenders from 57 chevy are the same as 55 to 57 gmc and inner fenders) and the 55 to 57 chevy uses chevy only front end components and the Canadian GMC is a hybrid of the two. I need to know what pieces are needed to combine the gmc grill to the chevy radiator support. Is it a simple "use this from chevy and this from gmc" or does the Canadian GMC have some parts that are Canadian gmc only?

[jmlloar]

The 58/59 already uses mostly chevy parts including the chevy radiator support and chevy hood.

My problem is: the 55 to 57 usa made gmc uses gmc only front end components (only the fenders from 57 chevy are the same as 55 to 57 gmc and inner fenders) and the 55 to 57 chevy uses chevy only front end components and the Canadian GMC is a hybrid of the two. I need to know what pieces are needed to combine the gmc grill to the chevy radiator support. Is it a simple "use this from chevy and this from gmc" or does the Canadian GMC have some parts that are Canadian gmc only?

I already have the support and radiator mounted and the chevy hood latch panel although it looks like I might need to use the gmc latch panel.