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Discussion Starter #1
Ok, now that mortec is gone cannot find out what they are. Can someone please tell me what I have? 781 are the last 3 #'s.
Thanks
 

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large oval port open chamber heads with small intake valves, work well with larger valves and some bowl clean up work, lots of guys love them 468-496 low comp mills.
 

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Thanks, do you know what size valves were stock?
 

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2.06 int x 1.72 exh and i think they have chambers in the 119-122cc range

heavy 3/8 valves should be maybe up-graded to 5/16 with the valve up sizing to lightin things up
 

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Discussion Starter #5
well, with valves that small that could be why it's not very fast. not inhaling enough.
 

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steelcomp was here
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Pretty common upgrade is to install 2.19/1.88 11/32" stem valves. With a good valve job and some minimal bowl work they will flow over 300, up to about .650 lift. Good for 600hp easy and with more work and a little better flow they will go 700.
 

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AKA Blownjet 468
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Or in other terms, you got 1 of the 2 best open chamber oval port gm castings made.. 049 being the other;)
 
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