Iron and Aluminum head comparison pics...

[ForcedFirebird]

I thought the aluminum upper end was taller, so I bolted them together...





Some more comparisons side by side...







I know the iron heads are in rough shape (before you say something) but they were free from a guy I bought a sway bar from.

I'm using a custom plenum, but only the FPR is as tall as the iron lower.

How tall is the 3400 plenum?

[Joseph Upson]

While you are at it why don't you put them on a scale and see what the weight difference is. Someone on the Fiero forum actually believes that because some GM spec listed the shipping weight for a ZZ4 350 with aluminum heads as a couple of pounds lighter than a 3900 V6 with the complete intake manifold on it which by the way only differs by a few pounds than the 3400 upper intake that the 3900 actually weighs more as opposed to there having been a typo or the 3900 is being shipped with several more parts.

It stands to reason that the 350 crankshaft, aluminum heads, block and camshaft are heavier than the V6s because they should be at least 4 inches or more longer.

[Guest]

Already putting that intake to use, eh?

The 3400 plenum is quite a bit taller (thicker?) than teh RWD upper. In the end they may end up being very close to the same hight. The 3.4 is shorter than the 3400 overall, whihc is probably where the idea that the genIII intake was taller overall.

I'll measure my upper later for you.

[ForcedFirebird]

Already putting that intake to use, eh?



I'll measure my upper later for you.

Yep, the first thing is going to be a gasket match and pocket port .

Thanx, the info will be helpful. For my upper/plenum is going to be custom, so I wanted to see how much room I had to work with. I'll keep ya posted .

[geoffinbc]

While you are at it why don't you put them on a scale and see what the weight difference is. Someone on the Fiero forum actually believes that because some GM spec listed the shipping weight for a ZZ4 350 with aluminum heads as a couple of pounds lighter than a 3900 V6 with the complete intake manifold on it which by the way only differs by a few pounds than the 3400 upper intake that the 3900 actually weighs more as opposed to there having been a typo or the 3900 is being shipped with several more parts.

It stands to reason that the 350 crankshaft, aluminum heads, block and camshaft are heavier than the V6s because they should be at least 4 inches or more longer.

LOL that guy is stupid. A fully dressed LS series motos (all aluminum) weighs 400LBS dry. That is what an all iron 660 weighs fully dressed. From what I have read of course. I have never weighed them.

[ForcedFirebird]

I will get around to weighing them, but I picked up an iron head just before an aluminum one. The weight is significantly less on the aluminum heads. I can easily carry the aluminum heads, one in each hand, and it takes two for the iron heads (to carry them without fear of dropping it).

[ForcedFirebird]

The iron heads weigh 81lbs which includes the upper plenum (maybe 2-3lbs), and the aluminum weighs 45lbs including the fuel rail.

Almost half the weight.

[SappySE107]

Should add those to the picture gallery

[ForcedFirebird]

k, can do that...

[ForcedFirebird]

Well here is the difference with the UIM's on. The Gen1 top is nearly 1.5" taller. I should be getting the 3500 top end soon, and will compare all three. I need to make sure it will fit under my hood, as of now, i have about 1.5" clearance with the Gen1 top.

Ben, once I get some photos of the 3500, I will put them in the gallery.

[grimmcs]

Does the 3x00 TB flange stick out further than the gen 1?

[ForcedFirebird]

Does the 3x00 TB flange stick out further than the gen 1?

No, or very little. The 3400 manifold just moves the TB a little to the pass side.

EDIT: They aren't very straight in the last pic, I was in the process of cleaning the garage...
http://www.thirdgen.org/techboard/v6...tors-mess.html

[ForcedFirebird]

Well, here is a 3.1 upper, 3400 upper, 3500 upper ends respectively...






I will get more pics tomorrow, after the Bud Light wears off and I feel comfortable handling the heads