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#1
01-13-2004, 08:15 AM
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I have 092 heads on my 389.Will I have to go to the taller valve covers when I go to a'67 061 heads?
A 400 and a 428 have the same bore.Would the compression ratio be the same on each if you used a 72cc head?If not why?Thanks! |
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#2
01-13-2004, 08:15 AM
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I have 092 heads on my 389.Will I have to go to the taller valve covers when I go to a'67 061 heads?
A 400 and a 428 have the same bore.Would the compression ratio be the same on each if you used a 72cc head?If not why?Thanks! |
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#3
01-13-2004, 09:37 AM
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No.
Yes. Fist fulla bullets and a chest fulla teflon.... -Biggee Smalls |
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#4
01-13-2004, 12:10 PM
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Going to the 061 heads.
You will either need the really thick Valve cover gaskets for rocker clearence. Or taller valve covers. The valve train geometry changed in 67. Thus requireing the taller valve covers. As for the 428-400 Question The compression should be the same if you use stock replacment 428 pistons with the dish in the center. Usually I'm found working on my Pontiac. If you want to find me Look for the white picket fence and all the old Pontiacs parked outside. And the half dissembled engine sprawled all over the driveway! 
__________________
Try calling CRUSHPROOF! 512-386-9889 |
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#5
01-13-2004, 01:28 PM
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No the compression ratio will not be the same on a 400 and 428 with a 72 cc head. Because a 428 has more cubes it will have a higher ratio than a 400 with the same 72cc head. More volume compressed into the same space = higher ratio!
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#6
01-13-2004, 03:20 PM
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Yes.....you will need taller covers
Yes. it is the same because the 428 pistons from the factory are dished. RAIV Don't leave home without it. www.musclecarrace.com
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http://www.stockappearingdrags.com http://www.stockappearingdrags.com Come on get off that lawn chair and drive that car like it was meant to be driven. 69' 400 RAIV Judge Conv... 12.86@107 Factory Stock 69' 400 RAIV Trans AM .....12.48@110 Factory Stock 69' 400 RAIV Judge HT..... 13.07@104 Factory Stock 73' 455 SD Trans AM........13's?? not run yet 66' 455 GTO Convert.........12.20@112 non original 63' 421 SD Catalina...........restored fast as h*ll |
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#7
01-19-2004, 05:02 PM
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Alright Brandon, tell Danny that about the tall valve covers!
 Hopefully he will check on the 428 pistons and valve springs for me!  (Hint)
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#8
01-19-2004, 05:09 PM
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Um Danny,
Goathead?  Do not use Early Valve covers on a 67 up Engine! The valve angles and size changed. That is why they went to the taller square covers.  Usually I'm found working on my Pontiac. If you want to find me Look for the white picket fence and all the old Pontiacs parked outside. And the half dissembled engine sprawled all over the driveway!
__________________
Try calling CRUSHPROOF! 512-386-9889 |
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#9
01-19-2004, 05:48 PM
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Actually I asked if he had a good set of the taller original valve covers for when I go from the 092s to the 061,he didn't think I needed them.
The guy that runs PPR(can't remember his name)said that CAT is comming out with a 3in main 4in stroke to make a 428 from a 400.That's what I am hoping to do depending on how long it takes to for them to come out
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