Twin_Turbo
Der Maulwurf
- Joined
- Mar 5, 2008
- Messages
- 7,575
No, thinning the isolator moves the pinion up, reducing the pinion angle. The diff hangs under the frame, not on top of it:
LSX mounts to C2-C3
- Thread starter 00fxd
- Start date
No, thinning the isolator moves the pinion up, reducing the pinion angle. The diff hangs under the frame, not on top of it:
You are correct about that. I see most people claiming that you can "shim the nose up". That is not possible.
Also, completely removing the rubber isolator (not a good idea) will raise the nose up leas than 3 degrees. If you cut in in half, you might get 1 or 1.5 degrees up.
FWIW, I have measured about 10 C3's and most, if not all, fall into 0 to 1 degree down at the pinion.
You are correct on cutting the isolator in half, I didn't want to remove it either. Guessing that only gave me about 1 degree. I also replaced the 2 upper diff crossmember mounts and I'm guessing that dropped the rear another degree or 2. Although I'm guessing those will settle over time again, but the old ones had 40 years to settle.
The other option I considered was putting a metal plate or shim between the diff and rear crossmember. But the geniuses at GM designed the diff so that you almost have to remove the whole crossmember to get to the diff mounting bolts.
Like I said earlier, we're probably working harder than GM did to get the geometry correct. But I had no interest in taking stuff apart again to try to find a vibration source.
The other option I considered was putting a metal plate or shim between the diff and rear crossmember. But the geniuses at GM designed the diff so that you almost have to remove the whole crossmember to get to the diff mounting bolts.
Like I said earlier, we're probably working harder than GM did to get the geometry correct. But I had no interest in taking stuff apart again to try to find a vibration source.
00fxd
Well-known member
Revelation.....
Just went out and had a look. I noticed that the back of the right side cyl head is situated way back on the block on my 6.0L. The rear surface of the head is actually parallel with the bell housing mounting surface. On the sbc I have on a stand I see that the right head rear surface is 1" foreword of the bell housing mounting surface. So I guess that is why the usual LSx mount plates move the engine ahead. So there is no cyl head interferance problems with the firewall. So now the heads may not interfer but now your driveshaft is too short and the trans mount does not line up. :lol:
Just went out and had a look. I noticed that the back of the right side cyl head is situated way back on the block on my 6.0L. The rear surface of the head is actually parallel with the bell housing mounting surface. On the sbc I have on a stand I see that the right head rear surface is 1" foreword of the bell housing mounting surface. So I guess that is why the usual LSx mount plates move the engine ahead. So there is no cyl head interferance problems with the firewall. So now the heads may not interfer but now your driveshaft is too short and the trans mount does not line up. :lol:
You've got about 1" of play (front to back) with the yoke on the trans. Keep in mind it's made to slide in and out on live axle applications. I know my motor fit with the setback plates from speedhound, so the engine will fit. The firewall is tight though. I would suggest the adjustable plates and find a good comprimise.
Btw, I think the only reason the earlier designed plates used their configurations was to line up the bolt holes from the SBC 3 bolt mount with the LS 4 bolt mount.
Btw, I think the only reason the earlier designed plates used their configurations was to line up the bolt holes from the SBC 3 bolt mount with the LS 4 bolt mount.
Ozzy
Well-known member
Maybe this is a really stupid question.
Does the LSX block P/N 19166454 have dual motor mount bosses? It looks like it in the photos.
Anyone?
Does the LSX block P/N 19166454 have dual motor mount bosses? It looks like it in the photos.
Anyone?
Looks like the standard LS mount bosses to me,
http://www.superchevyperformance.com/PhotoGallery.asp?ProductCode=19166454
http://www.superchevyperformance.com/PhotoGallery.asp?ProductCode=19166454
Ozzy
Well-known member
I thought the World LSX block had the same mounting points as the GM LSX block as they state it accepts all GM accessory mounts.
LSX TV reported hat the World LSX block has mounting bosses for both the LS series and the earlier SBC mounts.
" Like many World blocks, this one features priority main oiling, accommodates dry sump systems, and even has both LS and early SBC motor mounts"
From that info I reversed the thought and assumed the GM LSX block was the same in that aspect, guess that is what I get for assuming,lol.
LSX TV reported hat the World LSX block has mounting bosses for both the LS series and the earlier SBC mounts.
" Like many World blocks, this one features priority main oiling, accommodates dry sump systems, and even has both LS and early SBC motor mounts"
From that info I reversed the thought and assumed the GM LSX block was the same in that aspect, guess that is what I get for assuming,lol.
I put a LS1 in my 76 last spring and what I found was that most of the store bought mounts are set up assuming you are using the L460 or L480 trans that comes with the LS1. These mounts will put the tailshaft in the right place so you don't have to shorten the driveshaft. I used the 76 TH350 so I made my own mounts using a blueprint I found on LS1Tech.com and moved the holes 1 and 1/4 inch forward (moves the back of the motor back to where the SBC sits). Mostly just depends on what trans you are going to use. By the way I also had to extend the snout on the torque converter .400" to reach the flywheel. Someone sells a spacer to adapt the SBC flywheel to the LS1, but it was about $75/w the special bolts needed. good luck with the swap and LS1tech was an excellent source for info for me.
Dale
Dale
00fxd
Well-known member
Just came in from the shop. After some fussing around and modifying pinion bushings and hardware I'm feeling good about the whole thing. Now engine, trans are all where they're going to stay, I need to ask, what thermostat housing did you guys use?
Thanks, Frank
Thanks, Frank
greg75vette
The Traffic Baron
This is the one I plan on using, but haven't bought yet:
http://www.summitracing.com/parts/CSI-911LS1C/
I was all fat n happy to use this one until recently. This housing apparently uses a standard SBC stat, which I've known, but it doesn't quite function like a normal LS1 stat. It doesn't block off the same things, etc. Some people have modified the original (cut off the nose and reweld it straight) to keep the LS1 stat.
However, there seems to be a good amount of guys that have used this housing with no ill effects. I'll probably stay with this one.
http://www.summitracing.com/parts/CSI-911LS1C/
I was all fat n happy to use this one until recently. This housing apparently uses a standard SBC stat, which I've known, but it doesn't quite function like a normal LS1 stat. It doesn't block off the same things, etc. Some people have modified the original (cut off the nose and reweld it straight) to keep the LS1 stat.
However, there seems to be a good amount of guys that have used this housing with no ill effects. I'll probably stay with this one.
I went with these guys. It uses an LS2 thermostat (vette) that even has the heater hose divider within the water pump. I was also able to use the 68 lower hose with minor mods.
http://www.hotrodhotline.com/pr/2008/08synistermarch/
http://www.hotrodhotline.com/pr/2008/08synistermarch/
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