Hello all,
I am currently looking at an 84 that has the crossfire engine pulled out, that being said I'm trying to gather opinions on what I should do. Ultimately my goal is to get a C4 up and running quickly and with a tight budget as I am a college student currently doing an internship. I'm not looking to make much power, just a reliable daily that can be fun to drive on the mountain roads by my uni. The original engines that these cars were equipped with are in short supply so I am also considering an iron block LS swap, if I do go this route I'll probably do a basic build of a cam, gen 4 internals, and all the supporting mods, my power limiters being the A4 and the Dana 36 in the back. I'm going to list a few questions.
What is a realistic time frame for a swap like this assuming the engine is built and the harness is ready?
I know the big things I would need to do are the mounts, cooling system, accessory drive, and notching the K-member, I'm not too worried about the harness as that's basically what my internship is.
Would I maintain DIC functionality, or is that done away with?
I know that you can get the dash to work with a P01/P59 PCM but I haven't seen too many mentions of if the DIC also still works.
Will ABS and other features of that nature be an issue with the swap?
This is a big one for me, as much as I hate the extra weight and complexity, the roads are a dangerous place once they get wet and I'd like the peace of mind of knowing ABS will still work.
Will the 84 suspension cause issues in the front with the weight of an iron block LS?
I know the 84s had a super stiff suspension from the factory, I'm ok with a stiff ride, but I also drive 4 hours between home and college, some of the roads can get pretty rough.

All in all, I'm pretty sure my next car will be a C4, I'm just trying to figure out what is right for me.
Thanks

 

Realistic swap time? If you have everything figured out and purchased ahead of time, 3-5 days. You could do it in a weekend with an extra pair of hands and some long days. You dont have to notch the K-member.

A4 and Dana 36 are perfectly fine.

Not 100% on DIC functionality. I think you can have nearly all of it, but there will be some things missing.

I believe the ABS is stand alone on the 84 and unaffected. Someone else can correct me if I'm wrong, I'm not 100% clued in on all of the differences of the C4 through the years.

I'm not sure why you think the C4 will have issues with the weight of an iron block LS when the stock 84 engine was all-iron.

 

Suspension isn't that bad unless it's a z51... those were pretty stiff. If youre starting without all the 84 specific pieces, getting something gen 1 that works will be annoying short of going to a carb..... All else, see below.

No ABS to worry about on an 84.

DIC will work except for MPG read outs... who cares.

Iron block LS is all of 5lbs or so heavier... again who cares. The biggest thing would be some of the 84 specific things but even still... as easy as any other LS swap... if it is a real 84 hood though, save it because I don't think it'll clear without cutting. (The cold air ducting beneath I think would hit the valve cover as it is a bit wider... could be remembering wrong. Only seen 1 c4 with a LS swap. Hard to picture dimensions without having both on a stand but the 84 hood is pretty interesting underneath.

 

I’m all for an LS swap but there is a bit of engineering involved. I think I would go for an aluminum 6.0 liter if I was was going to go to all that effort. There are some good SBC crate options as well. A bit less challenging to swap a small block with a small block. I really like the ZZ6 EFI crate motor it would be a good candidate for an 84.
You said you want ABS so maybe an 84 isn’t the best option if that’s a must. The only safety feature on an 84 is a pillow on the dashboard for the passenger to hit their head on. If you learn to modulate the brake pedal ABS is not required but it takes a bit of practice.

 

IMHO Unless you are doing an alum block ls3 for weight savings, it isnt worth it.

you can reach more power than you will feel comfortable with on an sbc

afr makes 195 eliminator heads that flow ls3 numbers to negate any advantages the ls3 may have over the sbc

 

They're $2300 bucks and still flow 10 CFM less.
I only have $2500 in my entire engine/turbo setup.

So unless those heads are going to bolt on 200 HP, I'd say they aren't doing you any good for the amount of money spent.

 

Hey, it has seatbelts!

 

For that same $2300, you can buy an iron 6.0 with start/wiring/accessories/ECU, LS3 heads, LS3 intake, F-body oil pan, swap mounts, flex plate, crankshaft pilot bushing, have the engine bolted in and mated to the transmission, and literally have double the power of the stock 84 crossfire with tons of room to grow since you're still on the stock cam.

Or you can spend $2300 on heads and still not have an engine. Weigh your options.

 

Headers for the swap would not be cheap I would think. There is a price to be placed on time and aggravation for a first timer as well but that would differ from person to person.

 

if I remember correctly, c5 headers fit as long as you change the angle of the collector... there was a whole thread a while back and I think that's what ended up happening.

 

Yep. Cheap Amazon/Ebay type C5 headers. They are also 1-7/8" primary with 3" collector and cost $150-$200. Definitely require modifying the collector location and may require some primary massaging depending on engine location.

Also, the afr 195s are great but the engine will likely need to be stroked to 383 to get to cammed 6.0/6.2 power #s and then they still fall a little short. The afr 195s have great flow numbers but not a lot of .600+ lift cams being slapped in gen 1/2 blocks to take advantage of the flow. Then you will need to figure out the intake manifold issue as the stock c4 stuff isn't going to work well and mini rams and other intakes that might fit are expensive.

 

Someone is about to recommend a carburetor.

 

Thanks for all the replies,
I didn't realize that the 84s didn't have ABS, ABS isn't a requirement but it's a nice to have. How are the brakes biased on the 84s? I've read they're anywhere 80-20 to 60-40, I was assuming that 80-20.
As much as I'd like to swap in an LS3 those engines are going for around $3500 around here, where an LQ4 is about $300 complete. I'm trying to keep this college student budget friendly and basically just get this car on the road. My way of thought is get it driving and then every couple of months do some mods, keep it mostly bolt on friendly if possible.
No notched K-member? Is that with a specific accesory drive or does the LS just drop in?
It does have the CAI hood, but rather than eliminating that I think I'm going to 3D scan it and see if I can CAD up an intake that works with the LS and doesn't completely butcher the hood. I've got a good amount of experience with carbon fiber layups so hopefully I can get it too look half decent.
I hadn't considered the headers, I can get a set of C5 headers for pretty cheap and welding them up to change collector angle doesn't sound too bad, again, I'm looking to get this car in the road sooner rather than later, and if that means I end up pulling the engine in 6 months to get some real power I'm ok with it.

 

Notching the k-member is only necessary if you are going to run the a/c compressor in the c5/truck location (lower position bolted to passenger side of the block). If you plan on running a/c in a different location you will likely need a different style compressor and a specific mount to put it in the upper passenger side position near the head. No a/c, no problem.

 

Anything can be done, the question is what is the end result that you want? I chose to go the full resto-mod route, and so wound up spending $$$ and taking over a year for the swap to be done "right."

My basic package was an LS-1 build along with a 4L65e automatic transmission from Turnkey Engine Supply of Oceanside, CA. They provided a kit of sorts that included the engine, motor mounts (which had to be shimmed), wiring harness, Howell computer, shorty headers, all accessories with a serpentine mount including a/c compressor. I also opted for their premium package which included "big block" chrome coil pack covers, a hydro-dipped manifold and trim for the power steering reservoir.

I retained Corvette Masters of Maitland, FL to do the conversion for me. It took a lot of time, but there was a lot of work to do. Given the larger transmission, the cross-frame had to be notched and reinforced. And the longer length of the transmission including the tailshaft housing caused us to consider either shortening the driveshaft (which we didn't do) or reusing the original transmission's tail-shaft housing (which did fit.) We also found out that the early C4's had the engine and transmission custom fit during installation resulting in several millimeters of misalignment when the new transmission was mated to the included transmission adapter and the engine. That required about a 90 day delay as we sought out a machine shop to build a jig and machine the interface so it was correct.

The entire front end of the engine compartment was reworked to accommodate the swap. I purchased a new cross-flow radiator from Ecklers. A visit to Coastal Corvette (used Corvette parts) resulted in a top end radiator mount and air intake system from a '96; we reused the bottom end radiator mount from my original. A new fan box was fabricated by Corvette Masters containing two Spraul electric fans.

Lots of engineering by Corvette Masters went into making the installation look like GM had designed it that way. Cudos to Robby Hooper and his team.

The generic Howell computer came with some standard settings that were not proper for my installation. It was enough to get the C4 started and on the road, but terrible for the actual swap. I took it over to Faster Proms in Lutz, FL for a street tune by Jeremy Formato. Perfection!

Here's a video of the initial startup: https://photos.app.goo.gl/pBLWTz6Aam7UjkBQ6

And one of many shots of the completed installation


LS-1 in 1984 C4

So, yes, you can do a swap yourself in a "reasonable" period of time. My decision to go the resto-mod route has resulted in recognition from several national magazines including a 3 page article in Corvette Magazine, appearance in Vette Magazine, and 3 page article in Classic Corvettes magazine (Eckler's house publication.)

 

Dropping in an lq4 with about 330hp is going to be gobs of fun. The 84s are the lightest of the bunch as they have the least amount of electronics and systems. The brake bias I would say is 60-40. Thing doesn't nose dive and under hard braking the tail doesn't wag around like I feel it would woth that little bias.
Dear god that's beautiful but it also seemingly makes my engine bay look roomy. (And dirty... which it is lol) The headlights, lemans style? Does the upper mods in the front not allow for operation or was it easier to go that route if I'm seeing it correctly?

 

The headlight mod was made about 6 months before we started the engine work. I had purchased my '84 at the Mecum Kissimmee auction in 2013. It appeared to be in great condition; the previous owner stated it was a show car with only 18k miles on it and in the last 10 years had only been driven to car shows in his area. However, the clear-coat started pealing off after a couple of washes, and I decided to get her repainted. I had seen the LeMans headlight treatment offered by Breathless Performance and decided to make that conversion at the same time. The body shop doing the work suggested upgrading the lights to replace the circular high beam with an HID projector offering high and low beams. That coupled with the included rectangular low beams really light up the road for me at night, and I like the appearance.

 

I'm not much into AC, so it is something I could do without, worst case I can pull the engine and notch the member somewhere down the line, but we're still in the cold season for atleast a couple more months.

That's an amazing car you got there, I can only be inspired by what I've seen. I'm planning on keeping the stock LQ4 PCM just because ive gotten comfortable with tuning my truck.
what kind of misalignment were you seeing, was it lateral or torsional? I'm not too sure how I'd combat that level of misalignment but I'm sure I could figure something out if need be. Was the rad the majority of the front end work, or were there other aspects that needed to be changed to get the engine to fit.

Thanks for the insight, my truck is currently making 350hp crank out of the 5.3, so itll definelty be a fun car to drive, glad to hear that it doesn't nose dive to bad, and that that the tail doesn't wag too much. The tail coming out is one of my largest concerns, but that seems to not be as big an issue as I thought it was.

 

Here are a few pictures of the misalignment:


Here you can see the offset of the shaft in the housing with the bolts in place, but the yoke not installed.

Here the yoke is placed over the shaft and you can see the small gap at the bottom of the housing.

With the bolts tightened loosely, the shaft cannot move. Thus the machining required to get a good mate.

 

As I stated, the intent was to make the installation look like GM had engineered it. There is another post in this thread showing a swap with an air intake tube and air filter installed with a right angle bend. It fills up the entire space between the engine and the existing radiator. We wanted to improve the cooling and so removed everything in front of the engine once the original Cross-Fire was out. This the '96 radiator shrowd and mount for the top of the new one and reuse of the '84 for the bottom. The air intake, also from the '96, was off a bit in the angle needed to match up with the throttle body intake. Corvette Masters has a hot water tank that they can strategically bend plastic items, and they had to increase the angle a couple of degrees to match up.

Also the hood scissor support was removed from the right side and a piston rod support installed on the left to free up space for the a/c compressor. It was necessary to cut a rectangular opening in the fender wall for clearance of that unit.

The stock a/c dryer had the openings in the wrong place for the rerouted a/c lines, so one for a Camero fit properly and new lines manufactured for it.

I forgot to mention in the original post that a low profile oil pan was required and obtained.

I'm sure there were other adaptations made that I may have missed. I've got a ton of pictures as the install progressed, but am not sure what all of them are showing...