Build a hypothetical 3500HD.

someotherguy

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Hey Richard, from the top of the engine bay, does the engine sit lower in a 3500hd vs a standard GMT400?
Interesting question.. and I don't know for sure, but I don't really think so. Didn't measure but just eyeballing it, seems to sit in the same relative position. I looked at a bunch of my build pics and none of the ones I can compare are exactly the same angle, but if you look at the surrounding underhood items, the engine seems to be in the same position.

Vortec 7.4 in the '94 3500HD:
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Vortec 7.4 in my previous '96 C3500
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Don't let the master cylinder reservoir throw you off; the HD has a much taller reservoir. Also, can't use the fan shroud as that's a taller HD-specific part.

Look at the other things around the engine for reference. Particularly, the distance between the rear of the intake manifold and the recess in the firewall for the engine. Looks pretty close to same, to me. Probably the best point of reference I notice is where the air intake tube/MAF sensor sit in relation to the A/C accumulator.

Richard
 

skylark

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Interesting question.. and I don't know for sure, but I don't really think so. Didn't measure but just eyeballing it, seems to sit in the same relative position. I looked at a bunch of my build pics and none of the ones I can compare are exactly the same angle, but if you look at the surrounding underhood items, the engine seems to be in the same position.

Vortec 7.4 in the '94 3500HD:
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Vortec 7.4 in my previous '96 C3500
You must be registered for see images attach


Don't let the master cylinder reservoir throw you off; the HD has a much taller reservoir. Also, can't use the fan shroud as that's a taller HD-specific part.

Look at the other things around the engine for reference. Particularly, the distance between the rear of the intake manifold and the recess in the firewall for the engine. Looks pretty close to same, to me. Probably the best point of reference I notice is where the air intake tube/MAF sensor sit in relation to the A/C accumulator.

Richard
Looks pretty close to me too. Thanks!
 

boy&hisdogs

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There's one of those 3500HD's (the kind with the extended grill) that parks across from my work. It's 2wd but it's a solid axle with leaf springs. Should be pretty easy to SAS if you really want a 4x4.

On a side note, it also has the GOOD door handles, the kind where you press the button with your thumb and not the ones that break all the time like on the regular trucks.
 

618 Syndicate

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Interesting question.. and I don't know for sure, but I don't really think so. Didn't measure but just eyeballing it, seems to sit in the same relative position. I looked at a bunch of my build pics and none of the ones I can compare are exactly the same angle, but if you look at the surrounding underhood items, the engine seems to be in the same position.

Vortec 7.4 in the '94 3500HD:
You must be registered for see images attach


Vortec 7.4 in my previous '96 C3500
You must be registered for see images attach


Don't let the master cylinder reservoir throw you off; the HD has a much taller reservoir. Also, can't use the fan shroud as that's a taller HD-specific part.

Look at the other things around the engine for reference. Particularly, the distance between the rear of the intake manifold and the recess in the firewall for the engine. Looks pretty close to same, to me. Probably the best point of reference I notice is where the air intake tube/MAF sensor sit in relation to the A/C accumulator.

Richard

Looks pretty close to me too. Thanks!
Not arguing here, but if that's the case, what purpose does the filler panel under the grille serve? I always thought it was to hide a body lift.
 

someotherguy

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Not arguing here, but if that's the case, what purpose does the filler panel under the grille serve? I always thought it was to hide a body lift.
It's not a body lift. The frame is completely different from all lighter duty GMT400's, and I mean completely different. The core support and radiator are taller, so the filler panel takes up that gap so they could use a standard GMT400 grille. The whole idea behind the 3500HD design was to be a "parts bin" build using as many existing components as possible, while creating a low ingress/egress light truck capable of medium duty work. It's essentially an RV chassis (meaning coach, not R/V as in the squarebody designations) with truck bodywork.

To help illustrate the height difference in the core support, here's a pic showing where I adapted the auxiliary fan bracket from the '96 C3500 that was the engine donor for my project. Had to space the bracket using the leftover end link parts from a Hellwig rear sway bar on the bottom to make up the difference.

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My '95 3500HD had a larger fan on the driver's side, guess they figured they'd utilize the extra space instead of making a larger bracket. (I bought the truck crashed in the front) - ya know, the more I look at the pic, I'm wondering if it was an aftermarket fan. Too many years passed since and I only had that truck a little while. A closer look tells me it is; it's held in place with the plastic thru-fin style mounts and that yellow wire is someone's hack job wiring it up.

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Finally for further illustration on the frame/engine mount situation, I feel like while the 3500HD frame has a really deep crossmember under the engine, they put the mounts up high to match more or less the regular GMT400 engine position:

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Hope the pics help clear it up a bit.

Richard
 

Supercharged111

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You guys are just trying to make me regret passing that last one up, aren't you? I'm leaning toward getting a roller myself and cab swapping on over if I can do it cheaper that way. They're all work trucks and beat to crap with gutted interiors, not really what I envision travelling with the family in. Either way it's a project that I won't have the bandwidth for seeing how I'll be moving across the country in a couple of years.
 

someotherguy

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You guys are just trying to make me regret passing that last one up, aren't you? I'm leaning toward getting a roller myself and cab swapping on over if I can do it cheaper that way. They're all work trucks and beat to crap with gutted interiors, not really what I envision travelling with the family in. Either way it's a project that I won't have the bandwidth for seeing how I'll be moving across the country in a couple of years.
If you hunt hard enough, you'll find one that isn't beat. That '95 I bought had a minor crash in the front (easily fixed), was an ex-wrecker, but clearly was owned by a company that took care of it. 280K miles(!) and it still ran great (TBI 7.4/NV4500), front suspension was tight, and the interior was even still nice. Not too many HD's with Silverado trim level but this one had factory power windows/locks, cloth bench, etc. It had 6 nearly-new tires on it and I bought the truck pretty much for the cost of the tires.

Replaced the hood, grille, core support, radiator.. and did end up having the trans rebuilt as it had the typical synchro grind. 454CID sent me some valve covers as I had one cracked along the rail, causing it to leak. I kinda wish I'd kept that truck. 159.5" wheelbase would have been perfect for an extended cab swap. Sure looked sharp when I installed the freshly-polished Alcoas.

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We can keep this pressure up until you buy one.. :D

*had to edit and check my math, I said this was a 183.5" wheelbase truck? Wow.. let me crack open another bottle. 159.5"...

Richard
 
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someotherguy

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You're in my boat now, I just passed on one for $10k. Got me to thinking maybe a C&C is the easy way out. Their frames were a lot beefier than a regular 3500 and could be had stock with 4wd and a 4.10 gear. I'd do the 10' bed, that puts more truck in front of the camper which is especially beneficial if you have a bunch of camper behind the truck.
I guess I'm late to the discussion but yeah, C&C 3500 are typically going to be 4.10's, if it's a 3500HD (actual HD) they are 4.63 and 5.13 only, depending on gas or diesel. Dana 80 rear and 4x4's only aftermarket as mentioned. BTW those 4x4 3500HD's are REALLY TALL.

Richard
 
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