5.3L Heads Cast-Iron
07-22-2006, 01:45 AM
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5.3L Heads Cast-Iron I tried searching for information on this for about 30 minutes and came up with nothing.
Here is what's up:
I have a set of stock heads on my LS1. The driver's side head is cracked (small hairline crack between the intake and exhaust valve). When I first took the engine apart after purchasing it used, I noticed that some of the header bolts were broke off inside the driver's side head and noticed obvious tampering.
I bought a set of used 5.3L Cast Iron heads with 1500 miles from a friend for $100. I was thinking to myself that it is an exceptional price. They have 2.02" Intake / 1.57" Exhaust and are milled 0.030 (I may be wrong, but I am pretty sure that is what he said on the milling.
EDIT: I forgot to mention that they are ported and polished.
The questions:
1. Will these give me more power?
2. Are there really any big differences with them being cast iron?
3. Are there any fitment issues (will they bolt on with no modifications)?
4. Are my stock pushrods, rocker arms, and LS6 springs good to go on them?
EDIT2: Will these heads work with an MS3 or MS4? I was kind of worried about the MS4 with it have .649".
I apologize if any of the above questions seem obvious, I just want to make sure. I have my current mods listed below. I am hoping to get some power added from these heads, even if it is 10 hp. I really bought them for the durability and freshness over my current heads (80k miles).
Here is what's up:
I have a set of stock heads on my LS1. The driver's side head is cracked (small hairline crack between the intake and exhaust valve). When I first took the engine apart after purchasing it used, I noticed that some of the header bolts were broke off inside the driver's side head and noticed obvious tampering.
I bought a set of used 5.3L Cast Iron heads with 1500 miles from a friend for $100. I was thinking to myself that it is an exceptional price. They have 2.02" Intake / 1.57" Exhaust and are milled 0.030 (I may be wrong, but I am pretty sure that is what he said on the milling.
EDIT: I forgot to mention that they are ported and polished.
The questions:
1. Will these give me more power?
2. Are there really any big differences with them being cast iron?
3. Are there any fitment issues (will they bolt on with no modifications)?
4. Are my stock pushrods, rocker arms, and LS6 springs good to go on them?
EDIT2: Will these heads work with an MS3 or MS4? I was kind of worried about the MS4 with it have .649".
I apologize if any of the above questions seem obvious, I just want to make sure. I have my current mods listed below. I am hoping to get some power added from these heads, even if it is 10 hp. I really bought them for the durability and freshness over my current heads (80k miles).
Last edited by adillhoff; 07-22-2006 at 03:13 PM.
07-22-2006, 05:54 PM
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are you saying the heads are cast iron? a 5.3L Gen III head should be an aluminum head with a casting number of 862 or 706.
some of the 6.0L Gen III heads are cast iron
some of the 6.0L Gen III heads are cast iron
07-22-2006, 07:04 PM
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It is a cast iron head that was used on a 383 stroker LS1.
EDIT: Under more investigation I don't think that they are cast iron. Sorry for the lack of information. Are the valves the right size? I know they are a little bigger than stock.
EDIT: Under more investigation I don't think that they are cast iron. Sorry for the lack of information. Are the valves the right size? I know they are a little bigger than stock.
Last edited by adillhoff; 07-22-2006 at 07:13 PM.
07-22-2006, 07:07 PM
#5
cant guess on power without flow numbers, but thirty thousandths is a lot to take off a 5.3 head. they already have a smaller combustion chamber stock(62 or 64 cubic centimeters, i cant remember which). you'll definitely want shorter pushrods and notched or dished pistons for the valve reliefs.
07-22-2006, 08:03 PM
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They were used with stock length pushrods. I guess because it was a stroker that they were like that. I will check them out some more and get back at you with more information.
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07-23-2006, 01:55 AM
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I apologize for me being an idiot. I should've double checked the information before I posted this.
They are 5.3L Ported & Polished (About Stage III) Casting #862 with 2.02" Int. and 1.57" Exh. They were milled 0.030 because of fitment issues with the valve covers. The whole milling thing is really foggy to me because I have not been able to ask my friend about it. All I know is that they will fit with no issues.
So all I really would like to know is this: Can I use the MS4 cam with these?
What is a nice streetable cam to use with 5.3L heads?
They are 5.3L Ported & Polished (About Stage III) Casting #862 with 2.02" Int. and 1.57" Exh. They were milled 0.030 because of fitment issues with the valve covers. The whole milling thing is really foggy to me because I have not been able to ask my friend about it. All I know is that they will fit with no issues.
So all I really would like to know is this: Can I use the MS4 cam with these?
What is a nice streetable cam to use with 5.3L heads?
