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Discussion Starter #1
i have a chance to buy a set of as cast C5-R heads at a big discount. as far as i know they have never been ported or worked and are new in the box.

i was thinking i might be able to get them and not port them out all the way so that i could run them on my stock short block and then when i step up to a bigger inch short block in the future, just have them opened up to handle the extra cubes.

and with the LS7 parts coming available, i could probably get an intake and not have to have one custom made.

any thoughts?

also, i saw where andy @ AA has as cast AFR heads that they can custom port to bigger than 225 sizes. maybe the same logic could apply here as well. port them out small to run on your 5.7L and then when you get that forged 443ci motor open them up?

i just can't see spending the money on AFR 205s right now if i'm going to be getting a bigger motor in the not so distant future. you lose so much $$ selling barely used speed parts, i figure there has to be a better way.
 

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I believe that you'll have several other issues to overcome before you can run those heads. Other than port size, C5R heads have very small combustion chambers (39cc?), so your C.R. will be much too high. Also, the LS7 intake may not necessarily work.

I'd hold off on a head decision until you build your big motor. By then LS7 heads might be a relatively inexpensive route to major power.
 

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On the C5R heads: they're made for a large bore motor, and have small chambers. You'd have to get into the shortblock, and add dished pistons after doing some welding on the chambers. You might as well go big then.

If you are getting a serious discount on the C5R head, I'd buy, and put on a shelf til you're ready to build the big motor.
 

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Discussion Starter #4
ok, i forgot about the chamber size issue! duh!

so if i only want to get one set of heads to do double duty, what would you all recommend in the interim as a compromise? go with the AFRs and have them opened up (like Andy advertises) when i get the bigger motor?
 

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The C5R heads require a large bore motor and also require a different intake manifold. These wouldn't work.

I would go with the AFRs like Andy recommends.

Good luck,
Alex
 

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I have the AFR 225 Heads that have been ported and polished by a Winston cup guru in Houston. They flow a corrected 360 cfm anad work much better on my 427 C5R than did the ported LS6 heads that ate oil...
 
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