My first BBC

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Hump66

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I've always been a SBC guy but my FIL has a 427 that I'm considering for my Chevelle. Thing is, it's a tall deck. Anyone have any good build recommendations for it?
 

swampratt

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I was thinking Big Block Chevy when i seen it and I do like the 427"
But never dealt with the tall deck. I do know it is .400" taller and many like to stroke it 4.25" or more and run a long rod.

But I have always been one that tries what he has on hand to begin with.
Header fitment may be an issue and valve cover height can get into the other parts on the car like heater box etc.

What is the goal with the car? do you have an ET or MPH or gas MPG in mind..Is it an auto or stick car.. how strong is the rear end?

I have broke every 10 and 12 bolt GM rearend I ever had..and Now all my hot rods get 9" ford rears or better.

At a minimum I would port the heads deck the block or at least surface it and the heads.
Remove all sharp edges in the combustion space and during the porting i would rough up the intake runners to promote atomization.
I like compression and 10.3 would be a minimum. BBC likes duration and if you want a decent daily driver the old school comp Magnum 280H is a good one with 230@ .050.
Valve springs will need changed of course.
I ran 121 seat pressure in a 396" with that cam and they were comp cam springs.. ended up floating at 6700 rpm in the hot summer weather.. shimmed them to 135 seat pressure and all is good.

That one got 2.19-1.88 valves and that is part of the issue.. heavy valves.
Small blocks can get by with 110 seat for many cams Old school cams anyway.
And rev to 8000 rpm.

So many ways to go on this 427..The above is for flat tappet cams.. You may be into rollers I do not know.

How hot were your small blocks?
 

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