55 gmc - The 1947 - Present Chevrolet & GMC Truck Message Board Network

inboil · 01-04-2018, 11:04 AM

Hi everyone. Thanks for this great site!! Iam currently doing a frame off resto ona 55 GMC. The cab was damaged and I found a complete replacement from Classic Industries for 10k, with doors. The only problem is that it is a Chevy, not a Gmc. Other than the dash, am I looking at any other differences? I will use the original dash in the new cab if all else is workable.
Thanks so much for your help!!!!

Foot Stomper · 01-04-2018, 11:12 AM

Welcome!
Yes, the cabs are same so go ahead and swap your dash.

There's other differences in the trucks but not related to the cab.

Keep us posted on how it goes?

Post pics too, we all like pics.

inboil · 01-04-2018, 10:22 PM

Foot Stomper,
Thanks so much for the confirmation. What other differences should I be aware of--if any? I'm assuming the frames and wheelbase are the same, and most of the changes between the two would be cosmetic and trim related. Also, I am going to shorten the frame, as the customer wants a short bed. I don't see anything that would give any real issue--I will of course cut upstream of the leaf spring perches so as to maintain their proper distances.
Thanks again. I will order the cab and post pics asap!!
William

Foot Stomper · 01-04-2018, 10:52 PM

I'm not a fan of cutting frames so am not a good source of support in that regard.
Frames for GMC trucks are not the same as Chevrolet trucks in same years.
In other words, there's 4 different frames from 55.2 to 59 when you include both Chevrolet and GMC. I'm only talking 1/2 short box too!

There's a lot of folks on this forum that can add Intel on specifics and I'm sure they'll chime in.

Just don't assume anything and do your research. Ask specific questions and I'm confident you will get accurate information.

For example.... hood hinges and inner fenders, steering column and steering wheels etc are not the same from 55.2 to 59.

dsraven · 01-05-2018, 01:33 AM

it seems like the cabs are the same except for the dash. I would say go ahead and swap the dash and use the rest of the stuff as usual. will you use the same frame etc? if so, there shouldn't be too much to worry about as far as differences because it is the same frame as you started out with. if you are doing a front end swap for IFS then do some homework to figure out the axle centerline for the new front end. it will depend on tire size and amount of suspension drop. the front fender has an angled rear section so the more the body is dropped over the wheel the more exagerted the look becomes. it tends to look like the wheel is being stuffed into the rear of the wheel opening. most guys will place the new axle centerline about an inch ahead of the stock location. the best way is to mock it up and install a wheel,with the tire size that you intend to finish with, and see how it looks. it is a personal preference thing. I will say that the lower the body drop the worse the wheel stuffs itself into the opening. it is well worth the time to get it right before welding in something and having to live with it that way after.
the 55-57n frame is basically the same but the 58-59 frame is different ahead of the front spring hangers. the rad support is in a different location because the fenders are longer so the dimension from the firewall to the rad support is different and the frame is actually longer ahead of the rad support.

dsraven · 01-05-2018, 01:36 AM

the front fenders may also be different to acomodate a different grille style. best to keep all the original stuff to compare against the new replacement parts.

01-04-2018, 11:04 AM	#1
inboil Registered User Join Date: Jan 2018 Location: seattle Posts: 28	55 gmc Hi everyone. Thanks for this great site!! Iam currently doing a frame off resto ona 55 GMC. The cab was damaged and I found a complete replacement from Classic Industries for 10k, with doors. The only problem is that it is a Chevy, not a Gmc. Other than the dash, am I looking at any other differences? I will use the original dash in the new cab if all else is workable. Thanks so much for your help!!!!

01-04-2018, 11:12 AM	#2
Foot Stomper Registered User Join Date: Oct 2015 Location: Calgary, Alberta Posts: 1,252	Re: 55 gmc Welcome! Yes, the cabs are same so go ahead and swap your dash. There's other differences in the trucks but not related to the cab. Keep us posted on how it goes? Post pics too, we all like pics. __________________ So when is this "Old enough to know better" supposed to kick in? My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989

01-04-2018, 10:22 PM	#3
inboil Registered User Join Date: Jan 2018 Location: seattle Posts: 28	Re: 55 gmc Foot Stomper, Thanks so much for the confirmation. What other differences should I be aware of--if any? I'm assuming the frames and wheelbase are the same, and most of the changes between the two would be cosmetic and trim related. Also, I am going to shorten the frame, as the customer wants a short bed. I don't see anything that would give any real issue--I will of course cut upstream of the leaf spring perches so as to maintain their proper distances. Thanks again. I will order the cab and post pics asap!! William

01-04-2018, 10:52 PM	#4
Foot Stomper Registered User Join Date: Oct 2015 Location: Calgary, Alberta Posts: 1,252	Re: 55 gmc I'm not a fan of cutting frames so am not a good source of support in that regard. Frames for GMC trucks are not the same as Chevrolet trucks in same years. In other words, there's 4 different frames from 55.2 to 59 when you include both Chevrolet and GMC. I'm only talking 1/2 short box too! There's a lot of folks on this forum that can add Intel on specifics and I'm sure they'll chime in. Just don't assume anything and do your research. Ask specific questions and I'm confident you will get accurate information. For example.... hood hinges and inner fenders, steering column and steering wheels etc are not the same from 55.2 to 59. __________________ So when is this "Old enough to know better" supposed to kick in? My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989

01-05-2018, 01:33 AM	#5
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,333	Re: 55 gmc it seems like the cabs are the same except for the dash. I would say go ahead and swap the dash and use the rest of the stuff as usual. will you use the same frame etc? if so, there shouldn't be too much to worry about as far as differences because it is the same frame as you started out with. if you are doing a front end swap for IFS then do some homework to figure out the axle centerline for the new front end. it will depend on tire size and amount of suspension drop. the front fender has an angled rear section so the more the body is dropped over the wheel the more exagerted the look becomes. it tends to look like the wheel is being stuffed into the rear of the wheel opening. most guys will place the new axle centerline about an inch ahead of the stock location. the best way is to mock it up and install a wheel,with the tire size that you intend to finish with, and see how it looks. it is a personal preference thing. I will say that the lower the body drop the worse the wheel stuffs itself into the opening. it is well worth the time to get it right before welding in something and having to live with it that way after. the 55-57n frame is basically the same but the 58-59 frame is different ahead of the front spring hangers. the rad support is in a different location because the fenders are longer so the dimension from the firewall to the rad support is different and the frame is actually longer ahead of the rad support.

01-05-2018, 01:36 AM	#6
dsraven Registered User Join Date: Nov 2010 Location: calgary alberta Posts: 8,333	Re: 55 gmc the front fenders may also be different to acomodate a different grille style. best to keep all the original stuff to compare against the new replacement parts.



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