5.3 crankshaft spacer
If its used on a 6.0 it goes spacer then flywheel. On a 4.8/5.3 it is the opposite flywheel then spacer. Its used to support the converter nose and keep everything running true. The flywheels are also different a 4.8/5.3 is dished a 6.0 is flat.
You don't always need the spacer. The spacer is application specific and may not be needed depending on the year of transmission, what transmission you have and which crankshaft your engine has.
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Staging Lane
Joined: Apr 2013
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Also, to add, I needed a spacer with a 4.8 mated to a nv3500 BUT, I found one of the rare 4.8 specific flywheels that had the spacer 'built' in.
Also, if using the spacer, good luck finger longer flywheel bolts (For a manuel transmission application)
Also, if using the spacer, good luck finger longer flywheel bolts (For a manuel transmission application)
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Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 97
Likes: 0
From: chicago
so what you're saying is since i'm using a 4.8/5.3 on a 200r4 and the flywheel is dished i need a spacer? so what will happen if i dont use one?
GM sells a complete Flywheel, space and bolt combo for this kind of conversion (LSx to TH350/400). look for that, as it is much cheaper as a kit than getting the parts separately.
Picture a 40# weight full of trans fluid flinging around at 6,000 RPM with the front nose completely unsupported. If you're lucky, the only damage will be to the trans pump. But I would bet the bell and case (and possibly the floorboards and your feet) would suffer as well...
Picture a 40# weight full of trans fluid flinging around at 6,000 RPM with the front nose completely unsupported. If you're lucky, the only damage will be to the trans pump. But I would bet the bell and case (and possibly the floorboards and your feet) would suffer as well...
You will get really good at pulling the transmissions in your ride. 
There are two types of spacer. In your application you can choose to use either. I have used both, but prefer the bolt on type because I have access to a GMPP dealer where I can get them cheaper than most websites, same day and no shipping. You could use the type that slides on after the flexplate and doesn't require bolts if you can wait for (and pay for) it to be shipped.
The GM part is more expensive but more flexible, while the slip on will suit your needs perfectly.
The GM part (requires longer bolts): GM Spacer Longer Bolt (requires six)
One of the slip on versions: Aftermarket spacer
There are two types of spacer. In your application you can choose to use either. I have used both, but prefer the bolt on type because I have access to a GMPP dealer where I can get them cheaper than most websites, same day and no shipping. You could use the type that slides on after the flexplate and doesn't require bolts if you can wait for (and pay for) it to be shipped.
The GM part is more expensive but more flexible, while the slip on will suit your needs perfectly.
The GM part (requires longer bolts): GM Spacer Longer Bolt (requires six)
One of the slip on versions: Aftermarket spacer
TECH Regular
Joined: Oct 2011
Posts: 408
Likes: 4
You will get really good at pulling the transmissions in your ride.
There are two types of spacer. In your application you can choose to use either. I have used both, but prefer the bolt on type because I have access to a GMPP dealer where I can get them cheaper than most websites, same day and no shipping. You could use the type that slides on after the flexplate and doesn't require bolts if you can wait for (and pay for) it to be shipped.
The GM part is more expensive but more flexible, while the slip on will suit your needs perfectly.
The GM part (requires longer bolts): GM Spacer Longer Bolt (requires six)
One of the slip on versions: Aftermarket spacer
There are two types of spacer. In your application you can choose to use either. I have used both, but prefer the bolt on type because I have access to a GMPP dealer where I can get them cheaper than most websites, same day and no shipping. You could use the type that slides on after the flexplate and doesn't require bolts if you can wait for (and pay for) it to be shipped.
The GM part is more expensive but more flexible, while the slip on will suit your needs perfectly.
The GM part (requires longer bolts): GM Spacer Longer Bolt (requires six)
One of the slip on versions: Aftermarket spacer
There several variables , probably the least expensive and easiest way is the dished 4.8 flexplate and the slip on version , transdapt , and speedway have these available
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 97
Likes: 0
From: chicago
is there a easier way to put a trans in trying to put trans in w/o pulling engine. its very tight at the top of the trans i tried to pull the trans down some to get some clearance. i ended up pulling the engine out half way to get top and the 2 second from the bottom bolts out now its time to put it back in im just looking for a easier way
Thread Starter
Staging Lane
Joined: Jun 2011
Posts: 97
Likes: 0
From: chicago
Now im trying to figure out how to fit a detent cable on the tb?