View Full Version : 427 vs 454 build up


theflash
12-14-2004, 10:19:00 PM
The dark side has been calling me for a long time. I'm thinking of builing one of the two. The goal is to get some killer horse power and maintain some street ability. The car will see the track maybe once a year, and then mostly cruise nights. This wont be a daily driver, but will be taken to work on a nice day.

I'd like your opinions on which you would choose and how you would build it. I have always been partial to the 427 (just liked the way it sounds vs 454 for some reason). And that it is a faster, and higher reving motor. Hood clearance is not an issue, and I'd like to keep the budget within reason (no outrageous race parts). I plan on keeping my current drivetrain, with the exception of maybe a TH400. If need be, add a Currie 12 bolt or 9 inch to the wish list.

One question about heads to start. I hear the AFR (not that I am set on these) SBC heads have raised exhaust ports, is this true with the BBC heads as well? Just considering header clearance. TIA

rscamaro73
12-14-2004, 10:30:00 PM
Don't worry about the headers as much as the whole picture. http://www.nastyz28.com/ubb/smile.gif

The only thing that would sway me away from a 427 is the cost of the pistons being a bit more than 454 pieces. Other than that, everything else is the same, except the crank.

Heads.....I hear lots of different things....so I guess its a pic and choose sorta thing. Edelbrocks are ok too from what I hear (cheaper than AFR's).

Mike-78 Z-28
12-14-2004, 11:06:00 PM
Depends on what block and crank you have to start with.If you don't have a crank go the 496 route and put the 427 stickers on it.If you have a 454 build it and see why they discontinued the 427.

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1978 Z-28 purchased new by me -$6750
Click here (http://f1.pg.photos.yahoo.com/ph/someonehasthisid/detail?.dir=/d752&.dnm=aefd.jpg) to view present state photo
Look above for glory days.
1994 Formula
1982 350 S-10

ZS10
12-15-2004, 01:13:00 AM
<font face="Arial,Verdana" size="2">Originally posted by Mike-78 Z-28:
Depends on what block and crank you have to start with.If you don't have a crank go the 496 route and put the 427 stickers on it.If you have a 454 build it and see why they discontinued the 427.

</font>

I built a 427 just for nostalgia. Those three numbers have been synonamus with with 'hi-perf' since they were first built.

No disrespect to anyone, but 454 triggers the image of a rusted out, 8:1, 220 hp, half-ton truck. But, know that all other things being equal, inches wins.

As far as higher revving, bah! Either way, just put the rev limiter to 6500 and hope your shorts stay clean.

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73RS/LT/427

Mike-78 Z-28
12-15-2004, 10:25:00 PM
<font face="Arial,Verdana" size="2">Those three numbers have been synonamus with with 'hi-perf' </font>
You got that right!427 is no doubt a magic number.

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1978 Z-28 purchased new by me -$6750
Click here (http://f1.pg.photos.yahoo.com/ph/someonehasthisid/detail?.dir=/d752&.dnm=aefd.jpg) to view present state photo
Look above for glory days.
1994 Formula
1982 350 S-10

craggar
12-16-2004, 07:41:00 AM
I'm another who likes the sound of 427.I built mine because I got a deal on the pistons.If I was going from scratch I would build a 454 or 496.
My combo is
10.5/1
Edelbrock heads
Victor Jr intake
Was a Hyd. roller .617/.630,248/254 Dur.
The car runs mid 11's all day leaving it in drive with the exhaust on and is great on the street.

theflash
12-16-2004, 10:24:00 AM
<font face="Arial,Verdana" size="2">Originally posted by craggar:
I'm another who likes the sound of 427.I built mine because I got a deal on the pistons.If I was going from scratch I would build a 454 or 496.
My combo is
10.5/1
Edelbrock heads
Victor Jr intake
Was a Hyd. roller .617/.630,248/254 Dur.
The car runs mid 11's all day leaving it in drive with the exhaust on and is great on the street.</font>

Sounds pretty close to what my goal is (the deeper in the 11's the better http://www.nastyz28.com/ubb/wink.gif ). Thanks for all the input guys, I'd still like to hear more opinions and ideas. Also, how do you make a 496? Is it a different crank, or rods, or what?

BTW, did I mention I might put a blower on this http://www.nastyz28.com/ubb/smile.gif

craggar
12-16-2004, 10:57:00 AM
My combo will run deeper in the 11's if you drop the exhaust and shift manually.When i went to Mission it ran 11.teens at sea level with the exhaust on.

ddeennis
12-19-2004, 03:02:00 AM
well you could go the cheap.....nostalgia...way and build slobbering radical running 427 bbc.

i did but in a 396 version.

850 holley
victor jr intake
stock closed chambered '390 heads with porting and bigger valves installed
roller rockers.
solid 1969 ZL-1 cam 262/273 @ .050"
11.7 to 1 compression.
cheap summit headers
tci 10" stall braked stalled at 4500 rpms
4.56 gears
in street trim thru the mufflers in a 3600lbs car 12.10's at 114 mph 7200 rpms

slicks thru the mufflers mid 11's at 115 to 116 mph.....

it was radical for the street i think but the cool factor was high from others......."what you got in that thing" "damm that sounds tough" "holy craap"

oh and thats when im filling it up with 87 octane fuel.......yes it ran on that and was even raced ......throw in some premium fuel and a shot of 104 octane booster and hit the nitrous 150 hp shot and click off some stupid 10 sec runs.......cheap easy and fast.......keep it simple.....ran that combo pretty much the same for about 5 years......2 bolt main stock bottom end with the factory bolts from the 1970 block....oh did i mention it was unbalanced as well.....no big dollars used parts thru out

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1980 z28 3900lbs daily driver,414ci bbc,13.505 @107.19 mph w/2.15 60ft. 2.73 gears in street trim.

1981 camaro "the race car" as the kids say. 454 .060 over 13 to 1 comp.roller cam,nitrous, 4500 stall and 4.56 gears...severe traction issues,10.80's to low 11's @ 126mph....under recontruction on chassis

1986 ford pick-up "the tow rig" runs a slow 18.00 flat at 75 mph in 1st and second gear only.

theflash
12-20-2004, 04:28:00 PM
<font face="Arial,Verdana" size="2">Originally posted by ddeennis:

11.7 to 1 compression.

oh and thats when im filling it up with 87 octane fuel
</font>

How did you ever get that to run with that low an octane and that high a compression?

yody
12-20-2004, 04:58:00 PM
well you can enjoy the sound of the way your motor is pronounced while I'll be enjoyin gthe sound of 41 more cubic inches passing you by! http://www.nastyz28.com/ubb/smile.gif

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71 formula firebird, pro-touring, 468; AFR rectangle port, 11-1 compression, ultradyne 288/296 solid,...620HP, D+D T56 six speed, 19" CCW rims, Hydroboost, C5 corvette brakes.. currently being built(almost done)
http://geocities.com/codybouc/firebirdpage.html


http://geocities.com/codybouc/firebirdpage.html

craggar
12-20-2004, 05:28:00 PM
<font face="Arial,Verdana" size="2">Originally posted by yody:
well you can enjoy the sound of the way your motor is pronounced while I'll be enjoyin gthe sound of 41 more cubic inches passing you by! http://www.nastyz28.com/ubb/smile.gif

</font>

You'll need the extra hp to keep that heavy firebird up to the 427. http://www.nastyz28.com/ubb/wink.gif

yody
12-20-2004, 07:33:00 PM
yeah, to be honest, I will be extremely happy if my car even comes close to 11's with the suspesion, tire/wheel setup I got going. And heavy it IS!!

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71 formula firebird, pro-touring, 468; AFR rectangle port, 11-1 compression, ultradyne 288/296 solid,...620HP, D+D T56 six speed, 19" CCW rims, Hydroboost, C5 corvette brakes.. currently being built(almost done)
http://geocities.com/codybouc/firebirdpage.html


http://geocities.com/codybouc/firebirdpage.html

craggar
12-21-2004, 08:49:00 AM
I think it will be well into the 11's depending on how good you are at shifting that thing.

John Wright
12-21-2004, 12:35:00 PM
Aw Shoot! I thought this thread was about exotic, big inch SBC's. http://www.nastyz28.com/ubb/smile.gif

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John Wright