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Hello, I'm starting a new build, hopefully you enjoy, and/or find some posts helpful.
First, the Car:
This is my 1992 Corvette. Its a fairly basic model, not many options, but I preferred it that way. Its a LT1 / 4L60 (non electronic), with the stock Dana 36 rear with 2.59:1 gears. Its a BAM car - Bright Aqua Metallic, black interior, 275/40R17s at all 4 corners, standard (not ride control) suspension, standard (12" discs) brakes. I have both the blue transparent and body color targa top for it. Its more or less completely stock, other than the original base(non-bose) stereo is replaced with a basic aftermarket unit for now.
To me, I graduated high school in 1992, so I love late 80s-early 90s cars. I've really enjoyed this car, and just want to modernize a few things, and to have more power. I already had my engine, so I bought this car for the purpose of the swap.
Overall, my goal for this car is simply to make a car that I enjoy to drive. Its not a drag or track car. I will drive it to work in nice weather, and on nights out with my wife. So it needs to be comfortable and drive well enough in traffic.
The Engine will be a stroked LS2. I have this engine already. I had an LS2 purchased fro an earlier project, that eventually got a different engine. The LS2 is from a trailblazer, and it had worn out rod bearings. I forget now, but I think it was #7, which seems to be a common failure point on the TBSS motor. So I ended up getting it built up with a 4" crank. If I remember correctly, its:
2007 LS2, bored to 4.005" (58x)
Callies Compstar 4" crank
Callies rods
Diamond pistons, I think -2cc flat tops
Heads are the stock 243 castings, ported by Advanced Induction, with BTR dual springs/retainers
Fast 102 LSXR with a WARR 102 TB
Cam with be (to be swapped in) Comp 239/247
Compression should be around 11:8, and DCR around 8.5-8.6, if I remember correctly.
Heads might be small for someone doing an all-out build, but should have good driveability. I have seen several dyno sheets from 383s-408s with this cam, ported 243s, and they seem to make 600-615HP on the engine dyno. So we'll call it 600.
Transmission will be a 4L60e, I gave the details/goals to Performabuilt, and they are now building me a Level 2 pro race unit. The C4s use a unique tail housing, which bolts to a "C-beam" which then bolts to the rear diff. There is no other transmission crossmember. So they are building me an LT1 style 4L60e, as I can directly swap my 4L60 tailhousing onto it. I will need to cut about 3/4" off the output shaft when I do this, as the C4 trans has a unique output shaft.
Converter will be the tried and true Yank SS3600. I run their Pro-Truck 3200 in my GMC behind my h/c 6.0 liter.
Rear Axle will be a Dana 44 found in manual transmission C4s, mine has 3.33 gears and a limited slip (all C4 diffs are limited slip).
Driveshaft and axle shafts are all the stock aluminum ones. They are all in good shape.
Engine Control will be via Holley Terminator X Maxx (550-918 kit). I run the Terminator X Maxx in our GMC, and love it.
Headers will need to get figured out. I am trying to avoid the $1100 swap headers from BRP Musclerods. But I am not too worried, I'll deal with it when I get the drivetrain in and I Can take a few measurements.
Other than the exhaust parts, and the accessory brackets, I have everything already, or it's on order. Most everything else will be stock, the car is in good shape overall. In a future year, I'll redo all the suspension bushing, swap the front brakes to C5 units, redo the interior and stereo system.
*Hopefully* I will get this on the road by July. That will give me some tuning time before this years Woodward cruise.
This will be my 3rd LS swap. My background is automotive engineering (I'm an Eng Manager for one of the largest Tier 1 suppliers in the Detroit area). So I over-analyze everything. But at least I read the manuals I have an active family, so my time to go work on the cars is limited. I've been building cars since the mid 90s, a very wide range, from B18 swapped Honda's to owning an M35A2, with much of that time building off-road Jeeps and Toyotas.
I do have a decently equipped pole barn set up as my auto shop. This will be my first build with a 2 post lift, I'm looking forward to it. I was pleasantly surprised that the arms of the lift fit under the Vette without having to put any wood under the tires to lift it up.
First order of business is to pull out the old drivetrain and look at what I've got to work with. Relatively straightfoward process:
First to go is the C Beam that connects the transmission to the rear diff.
With that and the driveshaft out, the transmission drops out next. As I mentioned, this a 4L60 (so a 700R4). I believe the C4 changed to the electronically controlled version in 1994.
Here you can see the C4-specific tail housing. The C-Beam bolts to the large buildup area at the end, which functions as the transmission mount and rear pinion support. These are unique transmission cases, with a large V cast into it (in similar fashion to the K from 4WD truck cases), they are missing some mounting bosses found in other models, and use a short output shaft. Anyway, I'm only going to reuse the tail housing. The 94-96 models have the electronic VSS I need, so I have ordered one of those, which I believe bolts in place in this tailhousing, and should line up with the 40 tooth reluctor on the new transmission coming. (I hear I might need to clearance the tailhousing inside.
LT1 is out. Overall the car is very clean. The engine bay is the only exception. Looks like the rear and front of the engine both had some leaks. The oil pressure senders on the back, and some undetermined location on front. But the engine was a good runner, 82k miles. If anyone needs an LT1 in the Detroit area let me know, lol. My garage feels like one of those kid games where you slide the cars around to try to get one out of the door. I need to get a few of these project cars sold out and focus on keeping the ones I want to work on. That Valiant and my old CJ-7 are both on the list to go.
Considering my load leveller and chains are about 16 lbs, the engine is a little lighter than I thought. Guessing the factory aluminum heads are the difference, since I've always pegged SBCs to be around 550-560. So far, I have removed about 10 more pounds of stuff from the engine bay that won't be needed anymore. The old mechanical traction control (ASR), the air pump, the TPS module, vacuum controlled cruise control, etc.
A quick blast from the pressure washer has the engine bay looking better. I was out of degreaser though, so its still a little dirty.
Finally, the rear diff is pulled out, and we have the bare foundation to start working with.
Once the engine was out, I started to label wires. I have the factory service manual, which is extremely helpful and so far has been perfect on the wire colors. I started with labelling everything, and then am slowly trimming and removing the ones that wont be needed anymore. In general, the car is old enough to have physical wires for most needed things. The oil pressure, oil temp, and water temp all have senders which will be reused in the new engine. The AC will be retained as well, so I'm tracing all of those. In general, this would be quite easy to wire in a 3rd gen ECU. But with the Holley, I won't retain most of the power and grounds, since it has it's own harness.
I have the pdf of the service manual up on the TV so I can look at it as I work. I have a wireless keyboard/trackpad with me at the car, as climbing in and out of the engine bay is a pain in the back. But it's the best place to stand to work on the wires. These cars are low and wide. (Yes, nothing in my shop is clean or neatly organized).
For the rear Diff, I picked up a Dana 44 from a manual trans model. This one has a 3.33:1 (40T/12T) gearset. I think that should work well for my setup. I have seen the 4th Camaro guys tend to like 3.73s, but I hope to be ~400 lbs lighter than them (Goal is 3100lbs), and the torque from the stroker should help. I run 4.56 gears with 33" tires on my GMC, which borders on a touch too low, but works well with the heft of the truck. With the ~25.6" tires on the Corvette, Its about 10% less gearing than the Jimmy. I'm good with that.
I bought the diff 2 years ago, and then put it on the shelf. I was a little nervous cracking it open last week, but happily, the fluid was very clean, a good transparent honey color. The case cleaned up well, and theres no damage or cracks, which many of the Dana 44s I found had cracks in the case.
My stock 28 yr old engine mounts, however, were cracked and shot, so I'm waiting for a shipment from Rock auto with new ones.
Right now, I'm waiting on a lot of parts. So I putzed around with the lathe. I am no machinist, but I *have* watched a bunch of This Old Tony videos on youtube, so there you go.
I got the oil temp and water temp sensors cut down and rethreaded. The coolant temp is cut to M12-1.5 to thread into the passenger head, and the oil temp I cut to 1/8 npt, and will thread into the bypass plate down by the oil filter.
I also turned a small adapter piece that press fit into the return port on my TBSS power steering pump. I unclipped/removed the stock fluid reservoir. This piece presses in place, and is tapped to 3/8 NPT. The stock O-ring seal is still in place, which seals the base of this fitting to the pump body. So the press fit is only mechanical in nature to hold the fitting in, and does not make the seal. I'll be using a C5 style accessory drive (still deciding on which vendor to buy from), with a remote resevoir. I'm hoping to reuse the C4 reservoir, if possible.
My Lathe is as messy as everything else. Its a WWII era South Bend 9.
Install the Rear Diff: Waiting on new U-joints for the rear halfshafts. Should arrive Thursday.
Prep the Engine to Install:
>Install the new Cam, install/Lash the rockers and pushrods)
>Install the new Corvette Balancer
>Install the Holley 302-3 Oil pan
>Install the LS3 water pump
Then I can install the engine mounts (I think they are due to arrive by Friday), and put into the car for the first time. *hopefully* this weekend.
Otherwise, once those bits are in the car, then I'm waiting on the trans and converter, and I can get the whole drivetrain bolted in place.
I believe the Terminator X Maxx also arrives today, so I can start planning out the wiring. I want to upgrade the fuel pump wiring and probably run my Aeromotive Stealth 340.
Nice to see another ls swapped C4. Just got my terminator x installed but have to send my ecu back. 🙁
Are you staying n/a?
Yeah, I plan to stay NA. I want this to be a somewhat clean simple install, and I'm trying to simplify and reduce weight. I am hoping to get 100lbs off the nose, and get the weight distribution slightly more towards the back. I had this motor built (the short block was built by Billy Briggs racing engines, I assembled the rest) 5 years ago. It I was starting from scratch, I might consider it.
I think the power ratio should be about right for this car for what I want, without overwhelming the 4L60e or the rear end.
I plan to turbo my 71 GMC at some point, when I do a chassis swap My daily drive is a twin turbo Ford Edge, so I have a bit of everything.
So sick keep up the awesome documentation I have had a c5 and have a c6 right now, clearly I need a c4
Thanks!
C4s occupy a strange space. They weren't super fast by todays standards, but the cars, especially the LT1s aren't as slow a people think. They *are* sports cars, but also luxury/grand tourer type, rather than the track focus of many of todays cars. As such, the majority of them were automatics, with 2.59 gears. But they are still 13 second cars stock. And they come stock with 12 or 13" discs, up to 275 front/315 rear tires, and 315s fit all 4 corners without mods. They are low, lower than C5. Harder to get into for sure, but I love the feeling once you re in.
Today, you tend to have really nicely kept ones that are unmolested and never see snow, or you see nasty beaters. I think this is why you don't see a swap market for them. Beater people don't tend to want to put the money into a decent LS swap, and the other crowd is more old school, and rarely changes things. Combine that with the challenges of the transmission/c beam, and the fact that outside of the Dana 44s, which are in limited supply, there are no easy options to beef up the rear end.
Found a few minutes to work. Some parts arrived, but I'm still waiting on the engine mounts and U joints.
Time to get the engine wrapped up. I never enjoy pulling the balancer, and this time, the bolt had a lot of red locktite on it. But it came out in the end. Having the correct puller for the balancer makes life easy once that bolt is out.
I've seen people pull from the outer portion, and sometimes break those tabs off.
Here's the specs on the new cam. Off the shelf, but seems to work well in 400" motors.
In she goes...(Note... I did smear the assembly lube around, but I do that after the pic, so that I don't get grease on the phone...). Always remember to clean the cam well before installing it. I always find a few dirty spots that I wouldn't want in the engine...
Since I was out there, I swapped the valley cover bolts. The stock ones will hit the FAST manifold.
Hmm, the instructions say replace the 10 valley plate bolts.. but my plate goes to 11. Oh well, there's two are clear of the manifold, so I used the stocker on one of those.
Hopefully by the end of the weekend, the motor will be all buttoned up. I got the water pump and gaskets. Mounts are on their way, also have some ICT Billet accessory brackets coming.
Little steps, little steps. I've been trying to get out a few times during the work week and get some small task done. In normal times, I rarely work in the barn except on weekends, to have time with the family. But I'm working from home every day and the kids school is done until the fall, so I get more time to run out in the evenings.
I finished buttoning up the front of the engine. I couldn't find the blue locktite last time, so I found that and got the cam retaining plate and cam gear & chain reinstalled. I am switching over from the original TBSS pulley (I built this engine to go into a Jeep, it was going to retain the TBSS accessory drive), to a Corvette offset. I like to leave the front cover bolts loose until the pulley is on to get it centered in the front seal.
I use a 3 step process to get the pulleys on. First up is a piece of metric threaded rod which is plenty long to get the pulley started (sometimes the old stock bolt isn't long enough to get the pulley started on the crank). Once its bottoming out, I remove the threaded rod, and switch to the old factory bolt, since the 240 ft-lb torque spec is designed for that bolt
Finally, a fresh unused bolt for the last step of 37 ft-lbs + 140 degrees. Looks like I probably got about 130 degrees on the turn, but I never seem to get all the way there. I've never had an issue in the past, so I think I will OK...
Hopefully I will get back out there after work today. The U joints and water pump arrived (not sure if I have gasket laying around though). I might tackle getting the rear end back in the car.
My car is a low option model. A rare one with manual seats even. Removing minor weight where I can. I am hoping to be 3100 lbs or so. I should have the capacity to run in the 10s, if I ever get it to a track. My local track keeps getting shut down due to noise issues (Lapeer dragway).
Thanks, I've had it for about 15 years. Some guy was moving out of state and didnt want to move it. I snagged it on ebay from him for $400, including the workbench, 3 and 4 jaw chucks, steady rest, tons of toolholders and literally 2 buckets of mixed HSS and Carbide tools. 15 years later, I have never bought any cutter blanks, and don't think I need to for another 30 years.
Btw....you should have no issue running 10s. My bolt on ls6 did it. Helped a bud make his bolt on ls3 do it.....a 408 should have no issues going bottom 10s really. Hell I'm aiming for that with my rebuilt ls6 and if i get serious about a et I'll be looking for 9s.
Got my u joints, man they were a pain. Building 4x4s for 20 years, I've done dozens and dozens of U joints (I used to weld up my own driveshafts). These are Spicer non greasables, 5-3615x is the part (They're 1350 joints, but with a coating on the caps to not corrode the Aluminum driveshaft. These were super tight once the clips were in place, but a few well placed whacks with a brass drift and hammer and they loosened up OK.
Here's the Dana 44, all filled up (1.6 quarts of fluid total, including 4 ounces of friction modifier). The easiest way to tell a Dana 44 is there is no center bolt in the top of the cover
In contrast, here's the old Dana 36. Notice the top center bolt.
The casting is beefier on the 44 as well. There is a lot more material in the C beam mounting area as well.
Here's the weaker Dana 36
And its all back into the car. The halfshafts also serve as the upper control arm in these cars, so I wanted to make sure to have new joints in there.
04-27-2020, 08:17 PM
1992 C4 Corvette Build (LS2 Stroker / 4L60e / Terminator X) 
I have an active family, so my time to go work on the cars is limited. I've been building cars since the mid 90s, a very wide range, from B18 swapped Honda's to owning an M35A2, with much of that time building off-road Jeeps and Toyotas.
My daily drive is a twin turbo Ford Edge, so I have a bit of everything. 
