are these heads any good? 336781 oval port - Chevelle Tech
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post #1 of 14 (permalink) Old Aug 17th, 05, 3:28 PM Thread Starter
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Question are these heads any good? 336781 oval port

i have a chance to buy a set of these cast iron heads. # 336781 made between 1973 and 85. there suppose to be 113.0 cc. these are bare heads that were supposedly magnafluxed and found to be in good shape. anyone know valve sizes, and weather they'ed be good street performance heads when equiped with 2.25 intakes and 1.88 exhuast (if they would fit) valves. are these open ports?
i can get them pretty cheap, but i've learned cheap isn't always a good thing.

thanks john
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post #2 of 14 (permalink) Old Aug 17th, 05, 3:59 PM
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Re: are these heads any good? 336781 oval port

John,781's are some od the best open chamber BBC heads out there.
They will measure bigger than 113 cc (more like 118-120) unless they have been previously milled.
2.06/1.72 is the stock size
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post #3 of 14 (permalink) Old Aug 17th, 05, 5:18 PM Thread Starter
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Re: are these heads any good? 336781 oval port

thanks chris. i think there may be too many variables. i'll probably buy some new heads. if i ad the shipping and replacement valves with machining i'm within a couple hundred.

thanks john

ps if interested they're in ebay for cheaps.
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post #4 of 14 (permalink) Old Aug 17th, 05, 10:15 PM
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Smile Re: are these heads any good? 336781 oval port

John,

I have NO idea what you want to build or to what power level, but it has been proven that just a GOOD bowl-blend and "dingle-berry" casting flash port clean up on a set of 2.06"/1.72" valve BB large oval port heads really wakes them up!!

AND only after adding big valves AND then doing the same port and bowl work to them will bigger valves help make more power!!

I mention this b/c this is my "poor-man's shade-tree" way of doing things!!

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post #5 of 14 (permalink) Old Aug 18th, 05, 12:09 AM Thread Starter
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Talking Re: are these heads any good? 336781 oval port

thanks i'll look up pricing on new valves and machine work. not sure there would be much difference. i like the way you put that though.
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post #6 of 14 (permalink) Old Aug 18th, 05, 12:57 AM
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Re: are these heads any good? 336781 oval port

The 781 or 049 are the best ovals you can get. if you are sure about the condition and they don't need any seats replaced thay are great.

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post #7 of 14 (permalink) Old Aug 18th, 05, 11:20 AM
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Re: are these heads any good? 336781 oval port

I am in the process of having my 781's worked over as we speak. After cutting in the hardened seats with 2.19/1.88 stainless steel valves and some minor port work. I will be into the heads approximately $750. That is a LOT less expensive than buying a new set of aluminum heads.

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post #8 of 14 (permalink) Old Aug 18th, 05, 1:49 PM Thread Starter
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Re: are these heads any good? 336781 oval port

i was planning on buying "iron eagle" cast iron heads. they can be had for $1460 per pair. 2.30 intake and 1.88 exh. max .690 lift. thats with 345cc intake ports and 119cc combustion chambers.

john
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post #9 of 14 (permalink) Old Aug 18th, 05, 2:11 PM
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Re: are these heads any good? 336781 oval port

You don't need 345cc intake runners unless you have a 632 or something close.
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post #10 of 14 (permalink) Old Aug 18th, 05, 11:25 PM Thread Starter
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Question Re: are these heads any good? 336781 oval port

they also have 308 intake runners? what application would work best.
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post #11 of 14 (permalink) Old Aug 18th, 05, 11:59 PM
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Re: are these heads any good? 336781 oval port

for a complete rebuild of my 049 heads it cost me 315 bucks total. that was decked. valves reground 2.06 and 1.72 with a few new replacement thrown in the mix. seats done with 3 angle valve job and new guide liners installed with a set of "h.o." 427 springs and new retainers and keepers and umbrella seals.

this was from long's machine shop here in kansas.

mike stark from cfm said the 049 heads with bigger valves and pocket porting and casting clean up will flow about 300 cfm and support 550 hp easy.im using these heads on my 454 build up im doing now. port them and put bigger valves in them. so i guess i will spend alittle more money at longs shop to put the bigger valves in which is 100 bucks to cut them open for them. new valves can be had from competition products for under 100 bucks new.

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post #12 of 14 (permalink) Old Aug 19th, 05, 12:13 AM
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Re: are these heads any good? 336781 oval port

I am liking my 049's! "There so fine my OH Four Nines my OOOH FUR NINES!!!!!" Them there heads is so good the damn Beach Boys wrote a song about them!!!!

Craig
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post #13 of 14 (permalink) Old Feb 18th, 12, 2:33 PM
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Re: are these heads any good? 336781 oval port

Why is it i find sites that id the 336781 heads at 133 cc chambers?
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post #14 of 14 (permalink) Old Feb 18th, 12, 4:33 PM
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Re: are these heads any good? 336781 oval port

Dave ,did you notice the date of this thread?
Where are you seeing 133?
I see 113 to 118.

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