what is the difference if any between the L98heads(iron on the Z28) and the Alum L98 heads? Are the combustion chambers the same? intake runner and exhaust? I was looking at some ZZ4 heads, they are the same as the L98 Alum.. right? Does the ZZ4 heads have the right intake bolt angle for a 92 Z28 or will have to grind out the holes?

 

From the top:

Yea, the intake port is a little different, the exhaust port is D shaped and flows alot better.
The combustion chambers are nowhere near the same, the iron heads are 64cc(varies) and the alum. heads are 58cc(varies) with angle plugs and a 'swirl pad' that IMO is useless but there nevertheless.
The ZZ4 heads are the same deal.
The intake bolt angle is the old pre-87 style, so you will have to grind out the holes on your 92 intake. Its not too bad to do.

 

are the zz4 heads emmisions legal??and if so how much for them? and where is a good deal on them?

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white/gold GTA ,leather 5.7TPI 700r4 3:27posi twin cats,3"catback,aluminum d.shaft ported plennum,afpr,8mmwires,k&Nand all other "free" mods, performance resource chip,SLP cold air intake.

 

They dont have EGR passages in them, so they are only legal if you run a Corvette style EGR, which requires a stock Corvette or aftermarket intake manifold.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
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