GMC Topkick Single Cab Dually Pickup

[Vette_lover2004]

I’ve been slowly getting parts and kits together to finally start on this one while waiting for other projects to set up. Years ago, I saw one of these 1:1 conversions. I snapped a few pictures and kind of always wondered where that truck ever went after that. I never did find out but it always stuck with me.

Since getting back into the models, I’ve been able to finally recreate that same red truck I saw many years ago.

The conversion has to start with a base kit. The AMT 88-98 Chevy truck cab and dually bed from the snap kit is a start. Next is the actual hood conversion from Plaskit of the Topkick truck. And, a donor frame/chassis is required. I am using a Coca Cola Ford Louisville straight truck. I settled on an Iceman Collections Duramax/Allison combo for motor-vation.

The conversion kit itself is pretty straight forward. Cut off the fenders just above the body belt line and the cowl area. This leaves you with the cab ready for the interior and firewall conversion piece. There is one problem. You can’t glue the firewall in place permanently. You’ll never get the interior tub out. You need to the interior tub to align the firewall, so everything matches up as it should. 

My solution, was to glue in rectangle sections that tuck in above the backside of the door line, that allow the tub, glass, and firewall to slide in as a sub-assembly. Once everything is painted. The firewall can be CA glued or epoxied in place. Then all the other attachment points that hold the interior tub can be affixed as well. There is defintely some minor fitting required, and you must take your time to get this right, or risk ruining the cab, or worse, the hood. I did notice, that the cab extensions do not sit properly, and will need to be built up to mate with the hood. This is probably best to do, once the cab and hood have their final places, before paint. 
 

As far as the Duramax engine goes, it was a pretty straight forward assembly. There are no instructions, but you can watch a few YouTube videos and all will be revealed. That’s what I did and as you can see it’s together about halfway waiting on paint.

I figured this was a fairly interesting subject matter, and I don’t see these trucks often. Rarely, is a better word. Not many models have been made of these Herculean pickup trucks. Might as well add one to the fold.

Edited December 26, 2023 by Vette_lover2004

[stitchdup]

nice project, i think your pics is the first stock version i've seen. i'll be watching

[Vette_lover2004]

15 minutes ago, stitchdup said:

nice project, i think your pics is the first stock version i've seen. i'll be watching

Stock? Are you referencing the real truck or the model? 
 

I was under the impression that the real trucks were conversions from regular commercial straight trucks. Most I’ve seen on the web are much longer frames, where they unbolt the rear springs, slide them forward to the center of the dually bed wheel openings, drill holes, and bolt them back in place. Then, they bob the frame, and install a shorter driveshaft.

As far as the model, the ones I’ve seen on here were all extended cab trucks. I’ve not seen anyone do a regular cab truck. I figured it was probably a welcome addition. I’m debating on making it 4WD. I need to get the Louisville frame built now, then decide on how and where to mount the cab. I was looking for some smaller rims and tires. The 20” rims/tires that come in all the AMT kits are far too large for this truck. 19.5 tires are a better size, and I think that’s what the real truck was wearing at the time I took that photo.

If I go 4WD then all bets are off at that point and it just might get boggers and a decent lift. I’m also deviating from the 1:1 truck and installing a roll pan from the slammed release of the C3500. I saw pics of a real one like that and I felt it cleaned up the rear nicely.

A friend of mine, who is a master machinist, wants to make an oversized hitch ball for it, just for laughs.

[stitchdup]

8 minutes ago, Vette_lover2004 said:

Stock? Are you referencing the real truck or the model? 
 

I was under the impression that the real trucks were conversions from regular commercial straight trucks. Most I’ve seen on the web are much longer frames, where they unbolt the rear springs, slide them forward to the center of the dually bed wheel openings, drill holes, and bolt them back in place. Then, they bob the frame, and install a shorter driveshaft.

As far as the model, the ones I’ve seen on here were all extended cab trucks. I’ve not seen anyone do a regular cab truck. I figured it was probably a welcome addition. I’m debating on making it 4WD. I need to get the Louisville frame built now, then decide on how and where to mount the cab. I was looking for some smaller rims and tires. The 20” rims/tires that come in all the AMT kits are far too large for this truck. 19.5 tires are a better size, and I think that’s what the real truck was wearing at the time I took that photo.

If I go 4WD then all bets are off at that point and it just might get boggers and a decent lift. I’m also deviating from the 1:1 truck and installing a roll pan from the slammed release of the C3500. I saw pics of a real one like that and I felt it cleaned up the rear nicely.

A friend of mine, who is a master machinist, wants to make an oversized hitch ball for it, just for laughs.

I was meaning stockish appearing, the only ones i've seen have been customised (only see them on telly on this side of the pond)

[AZPartsLocators]

Are you going to scratch build the door handles? Or did the conversion kit come with them?

[Vette_lover2004]

5 hours ago, AZPartsLocators said:

Are you going to scratch build the door handles? Or did the conversion kit come with them?

It comes with them. I noticed the cab in this Coke monster truck reissue, is having bow out of the A Pillars…looks like I might use a 454SS cab as the plastic seems more rigid…

[Sergey]

Hello Joseph! Nice project!

I guess you are building non exactly the same truck, as on top pictures. It has different style (facelifted) hood, then Plaskit have.