roush 3500?

[93ztwo4]

^ most likly ur right

[El_Diablo]

agreed, especially after seeing that plate, nothing that really screams "roush performance"

[Joseph Upson]

What about the heads are different on the 3500 that isn't VVT? Every head I have had so far has been identical.

The combustion chamber, there is an earlier thread possibly the one covering the 3500 vs. 3400 differences that has a picture of the combustion chamber in which there appears to be a little rib or eye brow like raised area about half way around the perimeter of one side of the valves. In a set of 04 3500 heads I removed from one of my engines that particular feature was absent.

When I called in an effort to find an extra set of heads I was prompted for the casting number because there were two listed. Apparently a different design is used possibly based on whether or not the engine is designated for Flex fuel use in which all 3500s are not, hence the possibility the specially treated valves for corrosion resistance GM mentioned on their site is used in that particular cylinder head as well.

I also recall mention of a characteristic feature inside the port of the 3500 head that was also seen in the picture and that was absent from the cylinder heads I had also. Both can't perform the same with those differences and I suspect the latest design is the best. I don't recall the 05 G6 being flex fuel rated.

[El_Diablo]

pix?

[Joseph Upson]

pix?

I removed the heads from a good supposedly 0 miles engine to sell and didn't take pictures but definately looked at the combustion chambers specifically to see those features which were not there.

[SappySE107]

What casting number was it then? I need to see pictures of this.

[Joseph Upson]

What casting number was it then? I need to see pictures of this.

I can't begain to answer why I didn't take pictures of the heads but I'm certain of what I saw. They were removed from an 04 Malibu engine and apparently there is a new design clause associated with that vehicle engine that I have seen a few times during searches. I believe it has something to do with the flex fuel capability.

[93ztwo4]

well i will be taking my heads off to get them ported so i will take some picture then. but it wont be for like a month. so if it turns out that this is a flex fuel engine what would i need todo to run flex fuel?

[onefastV6]

I have several pics of 3500 head casting #'s from the many sets of heads that I have had in the past year. I also have a spare set in the garage at the moment. These range from 04-06 heads, so I will see if anything is different between what I have.

[Joseph Upson]

well i will be taking my heads off to get them ported so i will take some picture then. but it wont be for like a month. so if it turns out that this is a flex fuel engine what would i need todo to run flex fuel?

Not sure its worth the effort (flex fuel that is), to my knowledge one of the changes which may be used across all of the engines is in the valve corrosion resistance treatment.

GM uses some kind of photometry sensor that senses the level of alcohol in the fuel and the computer makes the necessary adjustments to take advantage of it.

[Joseph Upson]

Here is the casting number from the heads that I sold that were different;
12578523. I took that off of a picture that I have of the engine. Unfortunately I do not have a good number shot of the heads on my 05 engine for comparison.

If you look at the combustion chamber on the cylinder head on the first page of the 3500 vs. previous engines thread you will see what I'm talking about. There is no way you can not notice that "unibrow" ridge next to the valves and the heads I sold did not have it.

http://60degreev6.com/showthread.php?t=32367

I checked GM parts direct and they show a cutoff of 04-05 on the heads and then 05 or 06 up. The price is the same but if the heads were all the same the year would be from 04 to the present. The 3900 heads are different all together.

[El_Diablo]

the regular 3500 was done away with though so you cant go 04 to present

[Joseph Upson]

the regular 3500 was done away with though so you cant go 04 to present

Excluding the 07 engines for those who are not aware are all based on the 3900 block design having the same bore and a 3 inch stroke.

[onefastV6]

From all the 5 sets of 3500 heads that I have had I keep coming up with the same casting #12578523. The head pictured in the thread "3500 Differences from Previous 3x00s" was one of my heads, just extremely dirty at the time.

What other casting # are you saying there is?

[Superdave]

mine are casting #12578523 as well...