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That is basically what I'm doing, mating a 5.3L to an SM465 in a '78 K20. LS7 bearing, NFW1050 flywheel, except I used a 2005 Silverado 3500 clutch and pressure plate to mate to the flywheel. This allows you to not have to modify the flywheel in any way, and uses the full friction material of the clutch disc.
Nice. What part numbers did you use for the pressure plate and clutch?
Yes, it is recommended to replace the flywheel (or flexplate) and pressure plate hardware with new. The crank is in fact drilled though and can leak if the bolts don't have thread sealant on them.
I guess it could also work as a sealant but I don't think that is the design intent. The "sealant" on the threads is a spray on patch that is a locking mechanism like loctite. I forget the mil-spec that calls for them but they are pretty common in the defense industry.
Finally got my hydraulic SM465 bellhousing today. I can 100% confirm that the NFW1050 flywheel and 2005 Silverado 3500 clutch and pressure plate both fit perfectly under a 15530202 truck bellhousing. Several rotations of the engine and nothing scrapes or hits.
Finally got my hydraulic SM465 bellhousing today. I can 100% confirm that the NFW1050 flywheel and 2005 Silverado 3500 clutch and pressure plate both fit perfectly under a 15530202 truck bellhousing. Several rotations of the engine and nothing scrapes or hits.
I got mine all installed as well. I thought I was in good shape until I installed the exhaust. The slave cylinder and downpipe want to occupy the same space.
I have never seen provisions for a zbar on an LS. I think the best option is the newer style slave cylinder. Fully inline and inside the bell housing vs the old style.
Last edited by Josh Beverly; 06-08-2020 at 01:08 PM.
The early style SM465 bellhousing has the z-bar ball mounted to it, not the block. That’s also an option too.
Edit: I’m in agreement in thinking it might just be wise to stick with the original Z-bar (non-hydro) bellhousing so the mounting perch doesn’t stick out, and run an internal slave like you have listed above. Best of both worlds, hydraulic clutch and keeping the LS3 Camaro manifolds. Oh well, more $$, lol.
After doing a little bit more research, it looks like Speed Engineering makes a set of headers that, while not listed to fit 4WD, are reported by several people to clear the hydraulic and mechanical linkages with plenty of room to spare. At under $300 shipped, I think I may try a set of these out to see if they actually do clear. If not, I can always use them on the 1986 C1500 swap instead.
Speed engineering and Schoenfeld are the two headers I came up with. I was leaning towards the fully hydraulic throwout bearing because it's around $100 and lets me keep the manifolds. Also, the fingers on my release fork are messed up anyways. I should have replaced it but I decided to power through.
The other thing about the speed engineering website that turn me off was they are on backorder till July, they specifically say they won't fit four-wheel drive, and they claim you need to buy their spark plug wires to work with the headers. I don't know if any of that's true but if it doesn't fit I don't know if they're going to take it back when they have a big red note that says it won't fit.
That’s a great price on the bearing, have you ordered one up?
Yeah, they do state no 4WD fitment, but I’ve seen several builds online with pictures that show otherwise. I’m not sure why you would need their wires, OEM are pretty compact, and I’d just use ceramic boots over them. I’d understand not wanting to take the chance on those though. I’d really like to stick with external parts just for easier serviceability, but internal may be the way to go.
I have not bought the slave cylinder yet. I rebuilt the 5.3 from a bare block. I want to hear it fire up and sound healthy before I invest too much more money on external accessories. I will run with the LS3 manifolds and choose my next path/purchase after I hear it cough to life.
So I got confirmation on another forum that the Speed Engineering headers have been tried with an SM465 and the external hydraulic slave and they interfere. It does look like they clear mechanical linkage just fine though.
Since I’m already set up with the Camaro manifolds, I think I will just be going with the internal slave cylinder.
Don't know if this will help anymore, but you can keep a Z bar clutch setup with an LS.
I used the bracket SD bracket linked below. I had to grind/cut a tab off the side of my block to get the bracket to fit flush, but it worked. I also used the 621 bellhousing listed on this thread. This was all on my 66 chevelle, not sure how it would work on your setup. I have speed engineering headers, and I had to redo the geometry of the z bar to get it all to fit (Z bars seem to be very specific to model and year). If doing it again, I would look into a hydraulic setup more closely, though it all seems to be working well and feels good.
My build thread has some pics of the bracket and block tab that had to be cut.
I've seen and answered a lot of questions on putting a earlier Gen trans behind an LS motor here and in emails. I've done a Richmond 6 speed, Muncie, and T10 (in progress) behind LS motors. So I thought I would cut and paste the various answers in one post (also will remind my feeble mind what I did) If I make any mistakes or you have additions, please post.
Transmissions: Earlier Gen trans had a 6.66" long input shaft with a 0.59" diameter pilot bearing ID. Early T10s and Muncies had 10 spline input, later ones, TKOs, T5s are 26 spline. Richmonds can be either. The spline count will determine your flywheel/clutch. Ford trans have entirely different input shafts and trans/bellhousing bolt patterns. T5s that came from V6 f bodies have the ford trans/bellhousing pattern and wont even bolt up.
Bellhousings: Use a 621 BBC bell housing. It has the correct trans bolt pattern but is missing 1 bolt hole for the motor mounting. Keisler has a version with the added bolt hole. I bought one, it is a nice piece. SBC bellhousings have clearance problems, truck have the wrong diameter bearing retainer. Just get a 621. Be sure to zero it with offset dowels if needed. Some clearancing for the starter may be required.
Pilot bearing: LS7 PN 12557583. It's got the correct ID and seats in the outside flange of the crank. It does leave a gap between the taper on the input shaft, but the shaft does seat the full length into the bearing. There was an extended bearing offered aftermarket, but I dont see any advantage over the $15 LS7 bearing. There are reliable sources on the net that state the ID of the bearing is 22.7mm or (.894") . Don't know where they started, but they're wrong. The ID is 0.59.
One other note on pilot bearing removal. The LS cranks are drilled through the rear flange to the 7/8 journal (no idea why). The only thing that prevents oil from the pan leaking is a pressed in plug. If you use the hydraulic grease/bread method to remove the bearing, you can push the plug into the pan.
Flywheel/clutch: For 26 spline, I've used the LS1 flywheel/clutch. Info here indicates you're best off to buy matching flywheel/clutch combos. One note, the flywheel will be about 0.4" farther from the trans. This means the front of the disks internal splines will run off the splines on the input shaft. I've not heard of anyone having problems with this. It also means you'll need a longer throwout bearing (PT614037) compared to the BBC setup.
For 10 spline you can use a flywheel off an 05 Silverado 1 ton truck (Sachs 1050). It bolts to the crank and is drilled for an old school 11" BBC clutch. For pressure plate and 10 spline disk, just get one for any late 60s/early 70s BBC application. I think transmissions switched to 26 splies around 73, so you can even use this flywheel with a 26 spline clutch. The other advantage is that the flywheel is about 0.400" thicker, so the disk is correctly placed on the trans input shaft and the earlier throwout bearing and clutch fork geometry will be the same as the BBC application. Downside is that flywheels extra thickness comes with extra weight. Oh yeah, and the Sachs 1050 flywheel is about $60, and 11" clutch is only about $120.
The only modification with the sachs flywheel is that it comes with location dowels that need to be removed, no holes on the BBC pressure plate. And 3 of the bolt holes were too small on the pressure plate I got. I only bored them big enough to keep the plate correctly centered. Since there are no locator pins, it might be a good idea to have the flywheewl/pressure plate balanced together. I didn't on mine, but probably would if I did it again. Btw, one aftermarket company (Pace) sells this combo for about $700 with bellhousing, bolts, etc. http://paceperformance.com/i-5146180...rsion-kit.html
Flywheel/clutch bolts: I bought the GM bolts for the flywheel/crank combo. I'm not sure if all bolts are the same length/thread. Note, the flywheel bolts come with a sealant. The crank flang holes are drilled al the way through, without the sealant oil from the pan can leak through.. If you reuse them, they will leak. Buy new ones. For the pressure plate bolts, I use the ones specific to the flywheel. This is important on the Sachs 1050, since it's threads are deeper. Pressure plate bolt #12561465.
Throwout bearing: The thicker Sachs flywheel will work with the old 1.25" throwout bearing, clutch fork, and pivot ball. An adjustable pivot ball is always a good idea, and here's a good site for clutch for geometry. http://www.novak-adapt.com/knowledge/clutches_etc.htm
And the shallower LS1 flywheel will require a longer, about 1 3/4", GM throwout bearing (PT614037).
I've never done a hydraulic on this combo, so feel free to add your info.
Speedo/VSS: Most old trans have a mechanical speedo. You can use this but you'll need a VSS signal to the ECU to prevent stalling issues. Dakota Digital sells a pass thru VSS that can be put inline. It can be, but doesnt need to be, tuned to give correct speed and will still prevent stalling issues. It will not provide enough pulses per mile to get a DBW cruise control working properly. One note, Dakota Digital has an unlisted 8" extension cable if you dont have enogh clearance to mount the VSS directly on the trans.
Inspection Plate covers: The oil pan fills in the center section of the bell housing opening. There is a cover on each side that bolt to the block. PN 12558718 and 12561536. Updated numbers 24261712 and 24261713.
Tuning: I dont do any....but....I've had a problem with rpm hanging or even increasing on DBW ECU from auto trans cars when the throttle is dropped and clutch engaged. Not sure if it's related to trans, traction control, etc, but it went away with a manual trans ECU. Maybe someone can help with this.
An LQ9 with LS1 intake, Keisler LS 621 bellhousing, Ls1 clutch, Richmond 6 speed Attachment 615724
Sachs 1050 flywheel, pins removed, with 11" BBC 10 spline clutch.
Note 3 bolt holes are smaller and extra thickness of flywheel. Attachment 615725 Attachment 615726
And mounted to an 05 LM59 (flex fuel 5.3)
With a Muncie attached to a standard 621 bellhousing Attachment 615727
I'm wondering if a ls7 clutch and pressure plate will work with the nfw1050 flywheel mating a 5.3 with a 26 spline t10?
05-24-2020, 07:16 PM
