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#21
12-23-2007, 01:45 AM
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Re: 427?
[ QUOTE ]
I took a 454 2 bolt main block, put a 6223/3.76 steel crank with 7/16 dimple rods and 427 Keith Black hypereutectic pistons. Heads were 115cc 6272990 rectangular port with 3933163 intake and 4053/780 vacuum secondary Holley. Compression was 9.975 to 1. Ran on 93 octane and was about 520 HP...... Muncie M20 with 3:73 12 bolt. Tons of fun in my 1968 Nova.  The best part about it was it would rev as fast as a small block which is an advantage over a 454 in my opinion. Plus I love rpm's....  [/ QUOTE ] Did you have to use a block girdle or are they splayed mains? 
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#23
12-23-2007, 06:37 AM
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Re: 427?
Did you have to use a block girdle or are they splayed mains?
[/ QUOTE ] This was a stock 39999289 block with 2 bolt mains. No modifications are needed to do this. All you are doing is de stroking the motor from a 454 to a 427 when you use a 3.76 396/427 crankshaft. 427 and 454 both have a 4.25 bore. But you have to use 427 pistons with a 3.76 crank. 454 pistons will not work with a 3.76 stroke crank. Just as 427 pistons will not work with a 454 4.00 stroke crankshaft. If you use a 427 piston that is .030 bigger and a 3.76 stroke it is a 433 cubic inch. I have a photo of the bottom end of the motor I built. Let me know if you want more pictures. Hope that helps. Kurt
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#26
12-23-2007, 08:50 PM
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Re: 427?
No. Correct me if I am wrong but I believe that oval port (low horsepower) head motors came with hydraulic lifters and rectangular port (high horsepower) motors had solid lifters.
I ran a comp cams solid lifter camshaft with my motor and loved it. I could not afford a roller cam but I still wanted it to rev fast. I called comp cams and gave them all the information that they needed to help me pick the correct application for my motor. I highly suggest doing that unless you are going to build the motor 100% stock. They will need to know compression, intake, carb, power brakes, gears etc...
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 1969 SS396 Post Sedan Delivered to Van-T Topeka KS MCACN Day2 Concourse Gold Award 1965 VW El Lobo Dune Buggy built in the mid 70’s for the Iowa Shriners 1968 Schwinn Orange Krate 1969 Schwinn Pea Picker 1968 Schwinn 5-Speed 1970 Schwinn 3-Speed Deluxe 1972 Schwinn 10-Speed Continental 1973 Schwinn 5-Speed Suburban All Original Paint Bikes
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#27
12-23-2007, 09:02 PM
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Re: 427?
[ QUOTE ]
No,the 427 L-36/390HP & LS-1/335HP were both Hydra lifter engines. [/ QUOTE ] What about the L68 400 HP tri-power motor? I believe that is hydraulic camshaft also. But not sure. 
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1969 SS396 Post Sedan Delivered to Van-T Topeka KS MCACN Day2 Concourse Gold Award 1965 VW El Lobo Dune Buggy built in the mid 70’s for the Iowa Shriners 1968 Schwinn Orange Krate 1969 Schwinn Pea Picker 1968 Schwinn 5-Speed 1970 Schwinn 3-Speed Deluxe 1972 Schwinn 10-Speed Continental 1973 Schwinn 5-Speed Suburban All Original Paint Bikes
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#28
12-23-2007, 11:41 PM
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Re: 427?
The 512 block was used for 69 427 and continued into 70 as a 454. however, the 427 was internally balanced and the 454 was externally balanced. Because of that, the crank, balancer and flywheel must be for the correct application.
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#29
12-24-2007, 04:11 AM
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Re: 427?
[ QUOTE ]
The 512 block was used for 69 427 and continued into 70 as a 454. however, the 427 was internally balanced and the 454 was externally balanced. Because of that, the crank, balancer and flywheel must be for the correct application. [/ QUOTE ] I've seen this before so I thought I would ask. What is the difference between internal and external balancing?
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#30
12-24-2007, 05:24 AM
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Re: 427?
External balance used extra counterweights cast into the back side of the harmonic balancer, and the flywheel. Internal used counterweights on the crank, only.
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