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Confused about motor mounts for my LS swap

76k5blazerr

76k5blazerr

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Im in the process of putting a 6.0 LS into my 72 c10 and am slightly confused about which motor mounts I need to buy. This is my first 67-72 rig and my first thought was that the motor mounts were the "clamshell" style, like on my 76 blazer, but after looking, they are not, they are more of a flat plate mount with a square rubber piece in between the 2 pieces of the mount. What is this style mount called? Was this a 2wd/4wd difference or is it that the "clamshell" mount was not used until 73? So for those of you who have done an ls swap to a 67-72, which mounts did you use? Can I get away with just an adapter or do I need entirely new mounts? Thanks
 
Mine came from CPP. Look up in their catalog. It's the adapter and slider mounts along with their sheetmetal mounts that go to the frame. It's one of very few parts I'll recommend from them. Also, instead of using the factory v8 holes in the frame for the brackets, use the I6 holes which are the next ones back. That will help line up everything. I recommend their 4L60 tranny crossmember too.
 
I'd like to see a picture of what you are using.
CPP also has the standard piece you are talking about, similar to DirtyDingo etc etc, that allows adjustment of the motor in the cradle.

I can't even remember my stock ones :( truck got ripped apart rather quick
 
The clamshell mounts were only in the '72 big block trucks. Then in '73 everything got them.
Find a way to get away from the factory '72 mount, as @K85 Octane said.
 
The early ones used in 67-72 trucks (and most cars back then) only had one 7/16" bolt that secured the mount to the crossmember,mounted in rubber..they can pull apart,some replacements were designed with a safety "catch" so they couldn't tear apart completely..

I had a 454 in a '69 Suburban 4x4 chassis (under a '72 Chevelle Wagon ) and never felt confident those mounts wouldn't rip apart if I whaled on it..the '79 up clamshell motor mounts are pretty much bullet proof in comparison..
 
Yeah, the factory style is hard to trust. Trying to find the ones with the catch tab is difficult now too.
I have put a bolt from the engine side of the mount, which gives a stud sticking out towards the frame support. That works, but can make it a bear to install the engine.
 
I had the plate style mounts in mine before the swap. All of the crossmembers that I found were designed for the clamshell style so I switched. They aren't expensive and are better, so no reason not to.
 
ashman said:
I had the plate style mounts in mine before the swap. All of the crossmembers that I found were designed for the clamshell style so I switched. They aren't expensive and are better, so no reason not to.
Click to expand...
What goes into swapping in clamshell mounts? just a bolt on deal?
 
In that link I posted you'll see Norcalkid using the clamshell ones. He talks more about them in his build
 
76k5blazerr said:
What goes into swapping in clamshell mounts? just a bolt on deal?
Click to expand...
As I recall, you'll need adapter plates for the ls block, the clamshells will bolt to that and the crossmember will accept the clamshells.
I'm pretty sure I have pics and links to what I used in my build thread. Link in my sig.
 
K85 Octane said:
is this for a 2wd or 4wd? C10?
Click to expand...
Yes, 2wd c10? So basically, I can buy clamshell mounts as if I were buying them for any old truck, bolt them directly in place of my stock 72 mounts, then buy an adapter for the LS and bolt it on to the clamshells?
 
The motor mount stands, as I call them, are different for your truck vs. '73 and up.
I don't believe that it is a big deal to put them in a '72 though.
 
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You won't be able to use your stock crossmember. The oil pan is wider than a sbc.
 
lol I'm out

I don't know enough to be of any help. I just bought stuff and hoped it fit :rotfl:

I think there is a 2wd/4wd crossmember mix it up though but I'm keeping my mouth shut, I don't know enough to put my money where my mouth is ahahahahaha
 
K85 Octane said:
lol I'm out

I don't know enough to be of any help. I just bought stuff and hoped it fit :rotfl:

I think there is a 2wd/4wd crossmember mix it up though but I'm keeping my mouth shut, I don't know enough to put my money where my mouth is ahahahahaha
Click to expand...
Im with you, I was under the impression that i could use my stock crossmember and oil pan.
 
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