K1500 engines from GM include 454, and other related questions

[RokRoland]

Hi,

due to various vehicle modification laws it's required in some places (like where I live) to show you're not putting an unsafely powerful engine in your car or truck when doing an engine swap. For this reason, factory reference applications are useful for showing it can be done safely, because the factory has already done it.

So I have some questions that I hope someone could answer:

-Did GM ever put out a K1500 series GMT400 with a 454 of any sort?
-Apparently K2500 was certainly supplied with 454, is it true that non-HD 2500 is just a 1500 with bigger axles, torsion bars and springs so this could be seen as comparable?
- The C1500 did come with 454 in the SS version, but besides the main point of not having 4WD and coil springs in the front, are there any known differences?
- In 1996 Vortec engines with greatly increased power were introduced, there were at this point ABS and airbags added as safety features, but are there any other improvements affecting vehicle dynamics (I mean, refurbished interior does not count)?

Any assistance is appreciated - if any credible sources can be mentioned, even better - because the way it goes over here is there isn't a way to get a definitive answer whether something is comparable or not before you've actually completed the engine swap, and at that point it's a pretty dire situation to be pulling the engine out again and putting the old lump back because it can't be approved.

 

[RichLo]

Do you already have a truck that you are trying to modify or are you looking around for info into trucks that you can modify to you liking in the future?

Also, with your countries regulations, are they just looking for a SBC in a truck that had one from the factory or is there a HP/TQ limit to what you can stuff into that particular car/truck? Just asking B/C SBC's can be some real monsters that can look halfway factory if you want to go that rout. Like 427CI, 600hp+ naturally-aspirated with E85 fuel.

Sorry, not much help, but just inquiring more about where your coming from.

 

[someotherguy]

My responses in bold throughout your message -

Hi,

due to various vehicle modification laws it's required in some places (like where I live) to show you're not putting an unsafely powerful engine in your car or truck when doing an engine swap. For this reason, factory reference applications are useful for showing it can be done safely, because the factory has already done it.

So I have some questions that I hope someone could answer:

-Did GM ever put out a K1500 series GMT400 with a 454 of any sort? - no
-Apparently K2500 was certainly supplied with 454, is it true that non-HD 2500 is just a 1500 with bigger axles, torsion bars and springs so this could be seen as comparable? - a non-HD K2500 is very similar to a K1500 with merely a rear axle and spring upgrade
- The C1500 did come with 454 in the SS version, but besides the main point of not having 4WD and coil springs in the front, are there any known differences? - suspension as you mentioned, transmission, and rear axle
- In 1996 Vortec engines with greatly increased power were introduced, there were at this point ABS and airbags added as safety features, but are there any other improvements affecting vehicle dynamics (I mean, refurbished interior does not count)? - the usual reason for the safety features was U.S. federal mandate, not the available engines

Any assistance is appreciated - if any credible sources can be mentioned, even better - because the way it goes over here is there isn't a way to get a definitive answer whether something is comparable or not before you've actually completed the engine swap, and at that point it's a pretty dire situation to be pulling the engine out again and putting the old lump back because it can't be approved.

Assume you're asking because you wish to put a 454 into your non-HD 2500, the #1 issue, other than your local regulations, will be that your transmission isn't going to live through it, and the rear axle isn't up to the job, either.

Richard

 

[Biggershaft96]

BB swap would probably never work. Itd probably be smarter to go the ht383 route.

 

[RokRoland]

OK everyone, thanks for the input. I'll clarify a bit.

It is NOT my intention to put a 454 into my K1500 or to try to make the powertrain survive a big block and I am well aware a TH700R plus stock rear has to go as part of major power addition (though it is interesting point how much a NP241C transfer box can actually take).

My intention is to figure out the most powerful engine in the same application, or model series, that gives me a power figure which I cannot exceed by more than 20% for any engine swap. It does not matter if I want to put in a 383 or a 6.0 LS engine, I have to be able to show the limit is not being exceeded. Typically it is enough to show the rated output of the swapped engine unless it is obvious it's been modified, in which case a dyno sheet may be required.

An easy example for a C1500 truck is, the most powerful engine in the same model series is the 1991 454SS with 255 horsepower. This means into any C1500 I can drop in an engine up to 306 hp output, like a truck 5.3 LS engine, as long as brakes and other safety features of the reference truck (454SS) are matched.

However it appears K pickups are not considered to be the "same series" as the C series, so the main reference option is 210hp TBI 350. But with this option the 20% power increase ends up mere 252 hp which seriously limits options. But, if the 454 with 230hp were available in "the same series", then this engine could be used to get 276hp of allowed power, which means a 4.8 could be put in. It is still a bit unclear to me whether K1500 and K2500 are considered to be the same series, but if they are, I guess it is fair game since the 2500s had the 454 option.

OK, so you're asking why not just use the 1997 Vortec 350 K1500 with rated 255 hp as reference. That's why I asked in the opening post if there were any real upgrades that would warrant it not being a part of the same model series (the state agency has a database containing model series but this is not necessarily based on valid information as much as the opinion of some individual at one point in time). The immediate problem in any case is, this vehicle came with ABS on all wheels, and to use this as a reference vehicle means to retrofit ABS brakes to match the safety level - I don't know whether or not this is an issue, but at least it is more work.

It's not just engine swaps that require this calculation, but also putting a supercharger, turbo, or even changing cylinder heads or whatever. But practically, an engine swap or a power adder is obviously visible in the yearly inspection, engine internals are not, so coaxing more power by e.g. cam changed after successfully registering a swapped engine can be practically done.

So, as to get my numbers correct on what kind of power was available on the K1500 (or K2500), I asked the questions on the first post. Sure it would be easy enough from the registration point of view to just start bulding the 350 TBI but it's a bit expensive, still requires effort (obvious if EFI system has been changed which is practical must) and hits the limit pretty fast, when something like a LS gets that power easy and has much more potential on tap.

Not to mention that when the 350 eventually expires it would be nice to have the possibility to drop in a modern engine.

 

[RichLo]

Have you looked up C/K info on wikipedia yet?
https://en.wikipedia.org/wiki/Chevrolet_C/K

If you scroll down to 88-98 it gives some useful engine info you might be looking for.

You say you can swap in a cam after an initial inspection just not externals?

I'm just thinking, what if you put all the externals you want on it then choke it down with the internals to pass the initial dyno test. Then rebuild after its approved with the internals you want?

example: aluminum heads, headers, single plane manifold, carb/efi of your choice, etc. Except with 7:1 compression pistons, stock emissions cam, short-stroke crankshaft, etc.

 

[someotherguy]

Now that we understand your line of questioning...

It sounds like you want to go LS, so why not? Get a 4.8; that should fall under your HP requirement without any issue. Get your inspection, then turbo that sucker. The 4.8 is everybody's favorite budget boost engine. Next yearly inspection comes up? Pull the turbo and throw stock manifolds on. A bit of work but you get the platform you want and can build stupid power with it.

Richard

 

[RokRoland]

Have you looked up C/K info on wikipedia yet?
https://en.wikipedia.org/wiki/Chevrolet_C/K

If you scroll down to 88-98 it gives some useful engine info you might be looking for.

You say you can swap in a cam after an initial inspection just not externals?

I'm just thinking, what if you put all the externals you want on it then choke it down with the internals to pass the initial dyno test. Then rebuild after its approved with the internals you want?

example: aluminum heads, headers, single plane manifold, carb/efi of your choice, etc. Except with 7:1 compression pistons, stock emissions cam, short-stroke crankshaft, etc.

Thanks, I've scoured Wikipedia and even GM heritage center for info and whatever books are available as Google preview. These lead me to believe you could actually order a "light duty" 2500 with a 454, even though GM did not estimate to sell almost any of those. This info is not in Wikipedia (which by itself isn't a great source as anyone can edit it) and even some books say C/K1500 had a 454 V-8 option but I don't think this is actually true.

Problem with playing the tests is, it can be done and it is done by some, but there's a number of checks and anyway if you change the entire block you can't claim to have less than the rated power of the engine, or at the very least it's a question of showing you've reduced the nominal power in some verifiable way. So even if some guys swap entire engines in and out yearly it's a massive pain.

What I could get away with is a signed letter from GM saying that the model series of so called GMT400 K1500 pickups consists of 1988-1998 pickups in Chevy and GMC branding and that the models are in technical terms similar except for engine selection and some minor features. Just this statement would make it simple to swap a 305 horse engine without issue. Better yet, if it were to state the late light duty 2500 models were similar and available with the Vortec 454, that would be an easy way to put a 345 hp rated engine in a 1988 or later K1500 without much issue - not only for me but a whole bunch of other truck owners and save a massive amount of hassle.

But before trying to find some avenue to ask for such letter, I'd rather get my facts right, so I am asking on this forum before I try to embarrass myself in front of the corporate.

It sounds like you want to go LS, so why not? Get a 4.8; that should fall under your HP requirement without any issue. Get your inspection, then turbo that sucker. The 4.8 is everybody's favorite budget boost engine. Next yearly inspection comes up? Pull the turbo and throw stock manifolds on. A bit of work but you get the platform you want and can build stupid power with it.

Yeah, that'd work, unless there's an accident (massive insurance issue) or you get pulled over, sometimes even the cops are smart enough to spot a turbo when one isn't showing on the vehicle information system. And actually, with a 210hp TBI as reference engine, you can't even put the measliest early LR4 engine, because that's rated at 255 hp which is 3 horses too much... And yes they do nitpick, so even for this application a more powerful reference engine is needed.

 

[someotherguy]

Man, it sounds like any significant mods are a pain where you live.

As far as a 2500"LD" (7200 lb gvwr) coming with a 454, I would say I am about 99.9% sure it was never even an option. If a publication indicates it may have been, it's possible there's an error. That model comes with the light duty transmission - 700R4/4L60/4L60E depending on year (as well as the light duty examples of the manual transmission, if equipped) - and that's just not a combination GM put out the door.

Now I say 99.9% sure because obviously I don't know everything there is to know about these trucks. But, I've never seen nor heard of one configured that way and it does go against GM's logic they have followed on all their models of what engine/trans combos they offer.

Richard

 

[RokRoland]

Man, it sounds like any significant mods are a pain where you live.

As far as a 2500"LD" (7200 lb gvwr) coming with a 454, I would say I am about 99.9% sure it was never even an option. If a publication indicates it may have been, it's possible there's an error. That model comes with the light duty transmission - 700R4/4L60/4L60E depending on year (as well as the light duty examples of the manual transmission, if equipped) - and that's just not a combination GM put out the door.

Now I say 99.9% sure because obviously I don't know everything there is to know about these trucks. But, I've never seen nor heard of one configured that way and it does go against GM's logic they have followed on all their models of what engine/trans combos they offer.

Richard

With regards to modifications. Yeah it's not easy but people can manage various swaps, with loopholes or otherwise. So here I am trying to find one. But on the subject of 454s ,you may well be right, however the outlier would be the 454SS which came with the TH400 at first and 4L80E later (MT1 RPO) so there is precedent for putting heavy duty power line into lighter trucks with 5600 GVWR.