I'm looking to replace the heads on my LG4 305, which is also bored .040 over. I know some of Edelbrock's stuff doesn't fit the 305, but I was wondering if the bore would allow it. What are my other options? I'm looking for something with a nice HP boost without a tremendous price.

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1986 Firebird, LG4 305, bored .040 over, Crane cam, Edelbrock headers, Hooker Aerochamber muffler, loud and fast.

"Gimme fuel, gimme fire, gimme that which I desire!" - Metallica, "Fuel"

 

Well, if your looking for a HP boost without the drain of $$$, then Edelbrock is out. So far the only options are the World Product's Torquer 305 heads ($750/pair assembled) or GM Vortec heads (~$400/pair assembled) milled to 58cc.

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George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

 

Pretty much any head w/ 1.94/1.5 valves will fit. If you really want aluminum, corvette/zz4 heads will work. If you just want something cheap, even generic 350 heads will work, albeit at a loss of compression.
...ed

 

Where can I get the GM Vortec heads? That looks like a nice price. Are there any heads with a larger combustion chamber than 58cc that fit the 305?

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1986 Firebird, LG4 305, bored .040 over, Crane cam, Edelbrock headers, Hooker Aerochamber muffler, loud and fast.

"Gimme fuel, gimme fire, gimme that which I desire!" - Metallica, "Fuel"

 

Best bet go with the World Products S/R
torquer heads(58cc, same cc as yours), no modifications, it's a bolt on.And they have the bigger 1.94 1.50 valves. You can get the Vortech heads from any GM
dealer, but they have the 64cc heads which will lower your compression and you will need a new intake manifold, along with some minor mods.

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88 IROC the best RS ever made!
well except for the BC4s

 

Well, how much would an intake manifold that works nicely with the Vortec heads run? And how much of an HP boost would I get with either setup?

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1986 Firebird, LG4 305, bored .040 over, Crane cam, Edelbrock headers, Hooker Aerochamber muffler, loud and fast.

"Gimme fuel, gimme fire, gimme that which I desire!" - Metallica, "Fuel"

 

If you put the Vortec heads on there and new Edelbrock intake for then, you should expect about 50-60 horsepower. With good exhaust you should have even more. The LG4 exhaust and especially the manifolds, suck!

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92 Z28 L98 350
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Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires...

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

 

I've already got Edelbrock headers and an Aerochamber muffler on the bad boy. Hmm... How much should such a setup set me back for the heads and the intake?

 

I must disagree, you WON'T get 50-60 HP. The limiting factor in eiither setup is that lame camshaft. Maybe if you change the cam also. A Vortech package might well make
more power then the S/R heads but it will
be more $$$ and I don't think much more. What
your looking for the S/R heads will be best.

 

Well, I think I have a new cam that was installed by the last owner, but I'm not sure what it is. I've yet to take the engine apart.

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1986 Firebird, LG4 305, bored .040 over, Crane cam, Edelbrock headers, Hooker Aerochamber muffler, loud and fast.

"Gimme fuel, gimme fire, gimme that which I desire!" - Metallica, "Fuel"