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K5 Engine Swap - TBI 350 to Vortec 454

CUCV2

CUCV2

5/4 ton fun
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So, I've been working on this basket case of a K5 I got in a trade deal. It was really bare bones when I got it. Just a rolling frame and body. But it seemed like a good place to use up some parts that I had. Back story is that I had a bunch of 91 Blazer parts to put this together with. So, it's all toghether with a TBI 350 / SM465 / NP241 with the VSS. I go to turn it over. Nothing but a click. It turned over some when I installed the clutch on the motor so I thought it was good to go. But I ended up pulling six of the eight plugs (two are stubborn) and it turned over some more blowing rusty fluid out of at least one cylinder. But it won't turn over anymore. I'm guessing there is more rusty fluid (read water) in one of the two cylinders with the stubborn plugs. I put in some more effort on those and the plug breaks off clean with the cylinder head. Between this and the bad TBI unit, I'm thinking about just swapping in a Vortec 454 I have. Any thoughts from the CK5 brotherhood is appreciated.
 
Definitely a better use of your time than investing effort in that TBI 350.

Put a Vortec fuel pump in the TBI gas tank, run some FI fuel lines, work through a few wiring harness issues, maybe a bigger radiator, and some exhaust work and you should be well on your way. Obviously that's simplifying things, but the BBC will bolt right in and isn't too hard to adapt.
 
Or use the TBI wiring and toss a carb intake on it with an adapter plate and TBI it. That's the route I went.
 
454Sub said:
Or use the TBI wiring and toss a carb intake on it with an adapter plate and TBI it. That's the route I went.
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That's a good idea and would be simple, but with the TBI unit already being bad and probably needing upgrading to work with the 454, I was figuring he'd want to take advantage of the better injection system and not have to worry about it.
 
I've seen a few guys go the 5.3 route here too. That sounds like a great option as well. How involved is that swap compared to the Vortec 454?
 
Also, will the stock engine mounts and crossmember work for the 454?
 
Yes they will.

And the Vortec wiring and honestly the entire system sucks. It's harder to wire that mess in than it would be to just LS swap one. If your seriously considering that magnitude of a swap, I personally wouldn't run the Vortec FI.

Edit. I ended up running DIY engine mounts because with my stock crossmember I couldn't take my oil pan off and the balancer started rubbing after they broke down.
 
paratrooper307 said:
Definitely a better use of your time than investing effort in that TBI 350.

Put a Vortec fuel pump in the TBI gas tank, run some FI fuel lines, work through a few wiring harness issues, maybe a bigger radiator, and some exhaust work and you should be well on your way. Obviously that's simplifying things, but the BBC will bolt right in and isn't too hard to adapt.
Click to expand...



I am in the process of doing a 350 TBI swap for a 454 Vortec. But the project I'm working on is going to take some time and money. I have a donor vehicle that I got the harness and 4l80e from. I had a 454 Vortec engine, before I got the donor, and had it rebuilt because one cylinder had a verticle scratch that I wasn't sure of. The 454 was bored out .030 and an RV cam put in. I am slowly putting the top end together right now. It consists of new injectors, cleaning and painting the upper intake and all brackets.

I'll replace the ignition coil and sensors so I know they won't cause any start up problems. That will give me spares for the trails.

I am rebuilding the 4l80e and that will take a little while because as stated before, I'm not in any hurry. And because the tranny is longer than the 700r4 that is in it now, it will need the rear drive shaft shortened and the front drive shaft lengthened. That's a Tom Woods project.

I'm putting on headers and will need to build the exhaust since the kit that is on there now is getting old.

I had the harness, from the donor truck, worked on by @Team208Motorsports. Along with them tuning the PCM. It looks like it is half of what I sent them. They really know their stuff.

You would have to decide on what time and money you have/want to spend on the project. If you're wanting it done fairly quick, then do the LS swap. There is nothing wrong with that. And you get a really good running rig. Plus it seems to be the norm now a days. But then again, I'm not norm. I'm going for displacement and torque with some gain in HP. I can't wait to get this thing up and running but I know that it's going to take some time. I will pull the front end off the blazer to make removing and installing the set up easier. Plus I need to modify the transmission crossmember to go with the tall lift. And installing the ORD engine HD crossmember and motor mounts. While I'm at it, I will clean up some under hood and dash wiring including painting the engine compartment.

While all this is going on I can still drive my Blazer. I have plenty to do and I really don't want it down and not running when there is a slight chance of snow coming in the future. I don't plan on doing the swap until after the new year. With all my aches and pains I can't get in any hurry.

As far as the 454 Vortec system and wiring sucks. Nope. Can't agree with that. The wiring isn't any more complex than TBI. Different? Yes. But not difficult to work with. The system itself? Seems they can both have pros and cons. I just haven't found any cons with the 454 Vortec. Yet. Not saying I won't but until the swap is complete I have none.

When all is said and done, it will be one bad a$$ 87 Blazer. And I can say I built it the way I wanted it. That was my choice. :popcorn:
 
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I like the Vortec system as a whole. It seems to get decent power and efficiency as is. I am just a little confused about the install differences between an LS motor and the 454. If I sent the harness out, it would seem like a pretty bolt on affair. There are things to deal with like the exhaust, radiator, and figuring out which flywheel to use, but it still seems pretty straightforward. Am I missing something here? Why would the LS install be easier?
 
CUCV2 said:
I like the Vortec system as a whole. It seems to get decent power and efficiency as is. I am just a little confused about the install differences between an LS motor and the 454. If I sent the harness out, it would seem like a pretty bolt on affair. There are things to deal with like the exhaust, radiator, and figuring out which flywheel to use, but it still seems pretty straightforward. Am I missing something here? Why would the LS install be easier?
Click to expand...

The LS swap tends to be more common, so there's a lot more knowledge regarding it and a lot of people do more work with the computers, harnesses, and the like, so often times it's easier to get what you need. But with an LS you need adaptors to fit different motor mounts, if you want to use an older tranny then there are adapters and work-arounds you have to do there. There also tends to be little fussy things you have to do, like finding manifolds that fit, adapting sensor fittings to metric, etc, but all this is well known. A 454 will use the same mounts and usually will mate to your old transmission with a little less fuss and it fits because a big block came in those trucks. Most recommend using the ORD cross member or similar for oil pan clearance. As far as wiring complications, it's a pretty basic multipoint EFI, if you're getting the harness sent out you can have it set up to where it should fit nicely in your bay. I think most people just don't consider the electrical/fuel work worth doing when there are proven swaps with more advanced engines. That's just my take. It seems like it'd be six of one, half dozen of the other.
 
So, I'm trying to figure out what flywheel to use since the Vortec 454 was not offered with the SM465. Could I just use the same one as a TBI 454? Seems like there is some talk about internally and externally balanced engines.
 
Just scanned this thread. I’m doing THIS same thing right now basically. I’ve got my 73’ K5 that I’ve got two big block option directions to go in, or of course crate motor it. But I honestly Do want to run one of these two bone stock 454’s I’ve got. One is already a built completely assembled motor that just needs induction. Its a stock 89’ out of my crewcab. Its just been sitting for litterally 10 years after assembly! It was assembled with oil and assembly lube and all that, but its not been touched after it was assembled all those years ago.

I built that 454 for California CARB legal application, so it would be smog compliant. Of course that was for the 89’. Now the motor going in my pre-smog 73’, it doesn’t matter what I put in it. So my motor options are use this already assembled motor. Which I was going to turn into an engine shop and have them disassemble it, check Everything clearence wise to varify I did in fact put the motor together right, I want them to run and tune it. And since I can I want to possibly pop for a set of Aluminum heads for it, and put a better performing cam that works with the Al. Heads I get.

My Other motor option is a later model 1996 Vortec 454 with supposedly only about 60k on the odometer when it was pulled. I was going to run the Holley Sniper TBI setup on the 89’ motor. Not sure what I would use if I decide to just build the Vortec 454 instead. Everyone says the 96’ Vortec 454 is a better motor being the Next Geb BBC block, better stock heads. But for cost, just to get my Blazer running, driving again,

I should just finish the 89’ motor, save the Vortec 454 for another build. Which I’m cool with that too. I’m getting the itch for a hot rod again. But in due time. Only One thousand projects at a time, don’t want to take on too many more thousand projects at a time, I’m limited on time. Lol!!! :haha::haha::haha:
 
I came across a youtube motor builder channel where the guy is building a 620 HP 454 on a budget. Its a 91 pump gas motor. He is using the same motor I have basically. Sane GM rods. He saying this motor with handle 7k rpm. With be about 650 TQ. Thats what I’m looking to build. Thats Not a lot of hp out of a big block. In fact thats a mild build. Easily affordable and should yeild a turnkey daily reliable driver.
 
1.25 to 1.5 HP per cube is Easy to get out of a big block. Thats 454 HP out of a stock correctly build 454. 1.25 hp per cube is only 567 hp. 1.5 is an astounding 681 hp! If you can hit 1.75 hp per cube thats an 800hp BBC! Easily attainable with power adders like blower or turbo or even build naturally aspirated, which I prefer anyway.
 
I am getting ready to do this same swap as a winter project into my 87 blazer with 8 lug 44 in front and 14 bolt in the rear. I have a96 suburban with a vortec 454 and a 4l80. It has the push button 4x4 though will I need to change the transfer case??? I have looked into 208 performance and plan to have them do the harness work. any other suggestions would be a great help fist time messing with any fuel injection other then 80's tbi.
 
You'll need a passenger side drop t-case. For the 4l80e you'll need a 241 with the electric speedo/vss sensor or a late round pattern 205 with the vss sensor. Either could be converted if you can't find one.

The rest is pretty similar to any late model efi swap (like an LS) but there are many builds that have done them. One is @Capt Ron 's 77 K5 build as he just completed his vortec L29 swap a couple of months ago. Give it a read for the specifics.
 
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