Carb recommendation
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Joined: Mar 2001
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From: Medford, Oregon
Car: 1989 Iroc Z L98
Carb recommendation
Just curious what you guys think I should be running for a carb for my new motor. Here are the specs:
377ci (standard bore 383)
11.8:1 compression
Dart Race Series 220cc Heads (ported, should flow 310/210 @.700)
Solid Roller Camshaft (262/266@.050, .676/.625 lift, 106*LSA)
Super Victor Single Plane Intake
I would like to stick with a 4150 flange. Currently I have a 750cfm Speed Demon mechanical secondary carb. I plan on shifting this motor up around 7000-7200rpm.
What do you guys think I should look at for a carb? I have a friend who can get me an awesome deal on a Holley 950HP, not sure if a 950 would be overkill.
Let's hear what you guys think.
377ci (standard bore 383)
11.8:1 compression
Dart Race Series 220cc Heads (ported, should flow 310/210 @.700)
Solid Roller Camshaft (262/266@.050, .676/.625 lift, 106*LSA)
Super Victor Single Plane Intake
I would like to stick with a 4150 flange. Currently I have a 750cfm Speed Demon mechanical secondary carb. I plan on shifting this motor up around 7000-7200rpm.
What do you guys think I should look at for a carb? I have a friend who can get me an awesome deal on a Holley 950HP, not sure if a 950 would be overkill.
Let's hear what you guys think.
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Joined: Sep 2001
Posts: 2,308
Likes: 2
From: winthrop harbor, il & plymouth, il
Car: 1986 camaro
Engine: 383 sbc
Transmission: th-400
Axle/Gears: 4th Gen 10 bolt/Detroit TrueTrac 4.
well my dad runs a holley 850hp on his 460 hipo car and that is just about right. i think a 950 might be a little much for you. personally i would look more in the 750-850hp range.
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Supreme Member
iTrader: (1)
Joined: Mar 2001
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From: Medford, Oregon
Car: 1989 Iroc Z L98
My previous setup was as follows:
350, 9.9:1 compression, super victor intake, vortec heads, XE274 camshaft.
I picked up 1.5 tenths and 1.5 mph switching from a 650 speed demon to a 750 speed demon on that setup.
Maybe I should look into an 850 Mighty Demon?
350, 9.9:1 compression, super victor intake, vortec heads, XE274 camshaft.
I picked up 1.5 tenths and 1.5 mph switching from a 650 speed demon to a 750 speed demon on that setup.
Maybe I should look into an 850 Mighty Demon?
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iTrader: (1)
Joined: Apr 2002
Posts: 4,671
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From: Waterloo, Iowa
Car: 86 firebird with 98 firebird interi
Engine: pump gas 427sbc Dart Lil M 13.5:1
Transmission: Oldani TH400 w/ BTE 9" convertor
Axle/Gears: 31 spline Moser/full spool/4.11Rich
The truck I drive we had the 383 dynoed and it only pulled 653cfm at 100%VE and made 555hp/505tq. We're running a 750HP carb.
While on the dyno I suggested putting abigger carb on it, since my old 355 got quicker/faster with each jump in cfm rating up to the 950HP I had put on it. They said it owuld'nt do anything but hurt it, but I pushed and they installed a 850holley. Lost 20hp and our torque curve went to crap. Went from nice flat curve to a very quick peaky torque line, so we went with the 750HP.
Food for thought, the 950HP is overrated at the factory. All it is, is a 750Hp main body with 850 base plate and wet flows on the bench at 830cfm.
I love my 950HP, but with your combination that 750cfm carb is plenty. Start playing with spacers and I bet you pick up even more than what your at now. The 383 shot up 20hp with just the installation of a Wilson 2" tapered hole spacer, we tried the normal 1" 4 hole, 1" open, 2 inch 4 hole, and 2" open, then installed the spacer they called "***" and it gained the most hp, so $165 for 20hp ws a worth while investment
While on the dyno I suggested putting abigger carb on it, since my old 355 got quicker/faster with each jump in cfm rating up to the 950HP I had put on it. They said it owuld'nt do anything but hurt it, but I pushed and they installed a 850holley. Lost 20hp and our torque curve went to crap. Went from nice flat curve to a very quick peaky torque line, so we went with the 750HP.
Food for thought, the 950HP is overrated at the factory. All it is, is a 750Hp main body with 850 base plate and wet flows on the bench at 830cfm.
I love my 950HP, but with your combination that 750cfm carb is plenty. Start playing with spacers and I bet you pick up even more than what your at now. The 383 shot up 20hp with just the installation of a Wilson 2" tapered hole spacer, we tried the normal 1" 4 hole, 1" open, 2 inch 4 hole, and 2" open, then installed the spacer they called "***" and it gained the most hp, so $165 for 20hp ws a worth while investment
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