I have read about the 2nd generation heads listed above in the post about modifying our V6s. What I want to know is if anyone knows how the 2nd gen heads perform against the 3rd gen heads? I was originally going to do a conversion over the winter involving the 3rd gen heads but the intake manifold would also have to be changed. If the 2nd gen heads are comparible, that would be much more convenient.
Thanks,
Jim

 

The Gen II and III heads are FWD - You'll need a custom intake, either way.

 

I was told that the intake for the Gen 2 heads had the same port pattern as our rwd v6s. Is that wrong?

 

The only heads (that are worth a damn) that will work on our RWD intakes are the HO iron heads and are casting # 14054884

 

?
Vsixtoy, the article, "the V6 bible", that you posted (and was made a sticky) about modifying our engines talks about the gen 2 heads being better than the cast heads. It mentions the quick burn design and angled valve geometry along with a spark plug placement resembling a hemi design. So, that part of the article is wrong about the heads? And then, what motors have the heads that you speak of. I don't mean to sound like a smart a$$, I just want to understand.

 

The exhaust port patern is the same the intake port patteren is totaly different.
Find some Al heads on ebay and look very closely at the intake.
You will be fine if you can make a custom intake.

 

Customizing an intake is not a worry to me. I am trying to find the best heads for our motors.

 

Easy to find production heads, you found them.
The genIII heads flow as good as ported cast iron heads.
I think I will keep my Iron heads becase the stock Al heads might not beable to handle high boost and stay sealed.

 

Out of the box they are better. It also states that if you want a reliable performance head for endurance to use the cast iron heads and not the aluminum. The cast iron can be made better than the aluminum heads through welding ($$$) up the chambers for better quench and raising the floor of the intake runners. The aluminum heads are not durable for extreme porting from what I have read. They only used the aluminum heads for Midget racers strickly for weight reduction and they flowed decent for the smaller N/A 2.5l motors. The perfered heads are the Potter aftermarket design but I can not find any source for them (I would guess them to be about $4000 a set- compared to an out of the box aluminum GM production head for about $800) Both need specialized intake manifolds and will not work on the 3rd gen MPFI manifold.IF you can make your own then it is less expensive to use the stock alum heads over the stock iron heads, I poplan to use heavily modified iron heads and am going to lower the CC's and increase the quench for better burn.

 

ok although i dont know much...i heard u have to use the heads and get custom made rods to fit and then u can use the intake.
Go to www.60degreev6.com they have alot of info on this.

 

Ok, great. Sounds like that's what I needed to know.
Jim

 

In order to mix II Gen Aluminum heads with III Gen block, you'll need match hardware & software in the motor.

Hardware matching: Intake manifold / heads / block.

Software matching: This modified motor / EPROM burned.


Denis V.

 

This should explain better!
A pic is worth....