thunderbird 429

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May 10, 2008 | 09:52 AM

craig at ojo

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thunderbird 429

I just spent a day digging what's supposed to be a 68 Thunderbird 429 out of a friends shed. I have been told that the heads on this Engine will really improve the performance of a 460. The casting numbers on the heads are C8VE-E. Can anybody tell me about these heads? are they a good performance swap? I also have heard that the 429's are a lot better on gas than the 460's. any comments?
Thanks
Craig

May 11, 2008 | 04:11 PM

darrin1999

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From: fargo, nd

the reason theyd improve performance is because theyll raise your compression... if you have d3ve heads they have big chambers (95-99cc) and the c8ve heads have small chambers (72-77 cc) turning the stock 8.5ish-1 compression to 10.5ish-1 the reason i say -ish is because chamber volume on factory heads will vary a bit. the heads actually flow almost exactly the same. thats also the main reason they get better mileage- higher compression means better efficiency- up to the point of detonation. the 31 ci displacement difference doesnt make that much difference in mileage because what they were installed in was big and heavy... if you install a 429 and a 460 in a big heavy vehicle the mileage could be the same or slightly worse with the 429... if its a lighter vehicle then the 429 would win out on mileage... with a heavy vehicle you need more torque and thats what displacement gives you.