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#1
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Motor upgrade
Whats up guys I have a 76 455 car that I am restoring. Paint is done starting on the motor runs great now, but I have a set of 47 code heads I thank is off a 69 350 motor.Can I put them on my 455 or will it be to much compression ?Maybe one of you guys know the compression it will give my engine and can it be done .Thanks and look forward to reading your posts I always loved PONTIAC
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#2
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That 47 head has the small (2 bbl) valves 1.96/1.66 and 72 cc chambers. Bad part is the studs are press in. The compression at std bore would give you about 11 to 1.
I would dig up a set of 6x heads, depending on what your goals are there are better options out there. Welcome to PY though. Glad to have you.
__________________
Nothing is impossible if you break it down into possibilities. It's all a matter of "Want to". |
#3
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There are various 71 -78 Pontiac heads with large valves ,screw in studs & 96-100 cc chamber volume.
Look for cast # 96, 7k3, 4x, or 6x, just to name a few. (4x & 6x have BOTH have different chamber volumes available,so make sure you start with the smaller chamber versions) A 96 cc head on a 455 will give you (ballpark) 9.5 to 1 compression ratio,which is PERFECT for todays pump gas. |
#4
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Heads
Not sure what I have ? Still have a 400 motor out of a 76 T/A that I had 20 years in my dad's shop I know it's 6x code & My 455 is a 6x code both motors are stock & original motors someone gave me the 47 code heads . Can the stock heads be shaved to give me more compression. I think both motors are 7.6 to 1. I would like to keep the numbers matching I guess.The car still has AC & is a 455 4 speed car one of around 7500 made from what I can tell by T/A com . Not in any hurry to build runs good now and I drive it on pretty days I want around 350 hp & maybe drop the gear to a 373 just to make it fun to drive . going to be a many year Project !! Thank for the 411 I know bodywork well, but engine work is not my thing !!
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#5
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Pic
My car
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#6
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when I brought it home
My car
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#7
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Quote:
We would need the secondary codes off the 6x heads to be sure. but yes you can cut the heads up to about 60 thou. Each 5 thou removed is around -2 cc's. But need more info off the heads you plan to use. As far as the 3.73 gear I would lean toward the 3.42 for the street depending on your tire height. Any less than say a 26.5" tire will be an irritation on the highway even on short trips to the cruise ins...Your big 455 will like the 3.42 much better. Good looking TA...seems to be a lot of nice 2nd gens in NC.
__________________
Nothing is impossible if you break it down into possibilities. It's all a matter of "Want to". |
#8
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Heads
Just looked it's 6x -8 & I think its a 321 gear now Im learning alot !!
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#9
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Heads
Ok if 101cc 60 Divded by 5 is 12 x 2cc =24 101 -24 =77 / 114 60 Divded by 5 is 12 x 2cc =24 114cc -24 = 90cc Right??
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#10
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Quote:
But yes you have the idea.. Depending on your budget there are great affordable stroker kits out there to consider.
__________________
Nothing is impossible if you break it down into possibilities. It's all a matter of "Want to". |
#11
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maybe i'm missing something but wouldn't 75-80 cc be about 9.5 on a 400?
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FREEDOM ISN'T FREE BUT WORTH FIGHTING FOR |
#12
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Quote:
on a 400 75 cc's would be 9.52 on a 455 75 cc's would be 10.72 (the very edge of pump gas) He would be starting at 101 cc's on his current 6x head.
__________________
Nothing is impossible if you break it down into possibilities. It's all a matter of "Want to". |
#13
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okay i see said the blind man.i'm just used to thinking of 9.5 on a 455 being on the edge.
__________________
FREEDOM ISN'T FREE BUT WORTH FIGHTING FOR |
#14
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thanks
411 has been great! It's on the backburner for a few months need to find me a good machine shop
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#15
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Quote:
www.centralvirginiamachine.com Jim is much closer to you than I...more than worth the call..
__________________
Nothing is impossible if you break it down into possibilities. It's all a matter of "Want to". |
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