Well, it turns out I may not be able to go with my original plan to use Vortec heads due to legal constraints. What casting number head should I be looking for. My car is an 86 IROC currently holding the LG4. It will have a 383 (or 355) Extreme Energy 268 cam, headers, Flowmaster Force2 cat back, CCCS carb, Performer carb. I would appreciate all input. I know I can get great aftermarket heads, but they will cost more than what I can spend right now so I will just get what I can for the time being.

Thanks,
Mark

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1986 IROC LG4 "Bone Stock" (for now)

 

I wouldn't reuse the stock 305 heads- they will raise compression too much versus 64 or 76cc 350 heads plus they don't flow worth a damn.

I have 2 sets of 1987 cast iron L-98 350 heads laying around in good condition, ready to bolt on. They came off running motors and are complete with stock springs, valves, etc. and are in good condition. They're nothing special, performance-wise, but I'm only looking for $50 a pair (plus shipping which is another $70 or so).

They are early centerbolt heads that do NOT require self centering rockers, so you could reuse your vavletrain stuff off the 305 with no problems. 64cc chambers, 1.95/1.50 valves. No cracks, never milled, guides good, fresh seals, etc.

SHoot me an email if you're interested.

 

Look for ehe old "double hump" castings with bolt holes, such as 186 casting. They are particularly common on 69 & 70 Impala and similar "land barges", especially station wagons. Almost any 350 4-barrel in those applications and years would have those heads. They are completely compatible with all accessories and other details of 86 and earlier F cars, except for the rearmost exhaust manifold bolt on the pass side.

Casting # 3927186

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"So many Mustangs, so little time..."
ICON Motorsports

 

882's have decent flow numbers and respond well to porting according to CHP. Typically 72 or 76cc.

 

882's are kinds crappy, best are as said (and about the only ones you can use) are the 69-70 camel hump heads, everyone and there mother wants a pair of 69-70's as they are the only ones with assory holes so look to pay 200$ or more for a pair of CORES.

 

Check out Mortec.com. There is a complete list of sbc head castings there.
for a flat top 355 cu in. look for a 64 cc head. for a flat top 383 look for a 76 cc head. Either can be home ported for good
street performance. Try to find the '74 and older castings. They are a heavier casting.
Also consider the alumium L-98 Corvette
heads which port up nicely too.
http://www.mortec.com
Why are the vortecs illegal?

 

882's are not crappy heads. If Im not mistaken, they flow better than the aluminum Corvette L-98 heads, not to mention the iron F-body versions. I believe Vader posted some actual flow numbers a while back and the results were surprising.

 

The Vortecs don't have EGR provisions that I know of, at least the intakes that I have seen for them don't. So if I have to move ( I am military) to a state where there is a visual inspection I wouldn't pass. This is my assumption, I you could tell me otherwise I will go ahead with the Vortec's. Thanks for your help!

Mark



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1986 IROC LG4 "Bone Stock" (for now)

 

Technically that's true but you can get an external EGR kit to plumb exhaust into the cross-over passage in the intake and keep the EGR system functional. You'll need one of Edelbrock's intake manfiold's (I believe it's Edlebrock) to make this work.

Even if you DON'T use the external kit there isn't anyone who's gonna know the EGR isn't fuctional just by looking at it from the outside. Just leave it there and functioning, but even when the valve opens nothing will flow through it. No biggie in my book.

 

I found an EGR adapter at Summit that says: "EGR Adapter, Vortec 87-95 required to route exhaust to the EGR valve", Is this what I am looking for? It doesn't say if it 50 state legal or not. Now, correct me if I am wrong, I can use this with the Vortec head and intake manifold and still have a funtioning EGR system and that should be legal. Is this true?

Mark

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1986 IROC LG4 "Bone Stock" (for now)

 

882 heads may flow decent[don't have the numbers]but they had double heat riser passage and run hot,they are prone to cracking so examine them carefully. A good production gm head [heavy casting]that would be worth rebuilding if needed is 3998993 from 1971 up came on 350/400 sbc and would have 74/76 chambers to keep the compression streetable.The early double hump heads would raise the compression to high with flat tops and most of them have had numerous valve jobs already.

 

Check out GM performance parts intake manifold PN#12496820 It is a "performer" like intake for vortec heads that has a EGR boss and dual pattern carb pad. You'd need an EGR valve and some plumbing to the exhaust manifold to hook up a functional EGR system. But would be functionaly equivelent
to the stock EGR. Should be "smog legal" in all states.

 

I think you're on the right path. I have not done it myself, but what you are finding agrees with what I've read/been told.