How much HP?
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How much HP?
I have a 68 427/390
I put:
Torker II
Barry Grant Holley 625
Hooker Headers & Sidepipes with Hooker Maxflo's
Would any other info help?
If you feel a desire to be sarcastic or a big shot, please find another thread. Thanks guy's..
I put:
Torker II
Barry Grant Holley 625
Hooker Headers & Sidepipes with Hooker Maxflo's
Would any other info help?
If you feel a desire to be sarcastic or a big shot, please find another thread. Thanks guy's..
Last edited by Merlinhaggard; Aug 12, 2007 at 04:30 PM.
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From: FL
Just my opinion here, but you have some mismatched parts.
The Torker II is old tech but works OK. The Hooker headers are nice and will increase your exhaust flow but the 625cfm carb is choking that bigblock. That carb is good for a mild 350. With the 427, I would use at least a 750 or even an 850 cfm double pumper.
Any gains you made with the intake and exhaust, you lost with that tiny carb. So, I'll say maybe 390 HP.
The Torker II is old tech but works OK. The Hooker headers are nice and will increase your exhaust flow but the 625cfm carb is choking that bigblock. That carb is good for a mild 350. With the 427, I would use at least a 750 or even an 850 cfm double pumper.
Any gains you made with the intake and exhaust, you lost with that tiny carb. So, I'll say maybe 390 HP.
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From: Millington Illinois
St. Jude Donor '08-'09
Just my opinion here, but you have some mismatched parts.
The Torker II is old tech but works OK. The Hooker headers are nice and will increase your exhaust flow but the 625cfm carb is choking that bigblock. That carb is good for a mild 350. With the 427, I would use at least a 750 or even an 850 cfm double pumper.
Any gains you made with the intake and exhaust, you lost with that tiny carb. So, I'll say maybe 390 HP.
The Torker II is old tech but works OK. The Hooker headers are nice and will increase your exhaust flow but the 625cfm carb is choking that bigblock. That carb is good for a mild 350. With the 427, I would use at least a 750 or even an 850 cfm double pumper.
Any gains you made with the intake and exhaust, you lost with that tiny carb. So, I'll say maybe 390 HP.
Last edited by 63mako; Aug 12, 2007 at 12:53 PM.
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I just figured that since I started at 390, which I have heard its really underated by GM and is closer to 400/410. Then adding the Torker II which is much different than the stock intake and the BG Holley which has to flow better than the stock QJ, and the sidepipes I would guess:
Stock 390/400 HP
Torker 20 HP
Holley 20 HP
Pipes 20
Atleast 460HP????
Stock 390/400 HP
Torker 20 HP
Holley 20 HP
Pipes 20
Atleast 460HP????
Melting Slicks
Joined: Dec 1999
Posts: 2,116
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From: Mid West
Cruise-In III Veteran
I doubt you got 460HP, but the torque should be awesome. I have a 455 Olds that produced in the mid 400 hp range, but the torque was awesome - over 500 ft-lbs of torque near idle. It ran 12.0 sec 1/4 miles and was a blast to drive. It's currently torn down for a complete rebuild.
Torque is what you want for street use any ways. What's that old saying ....... horsepower sells cars, but torque wins races.
Torque is what you want for street use any ways. What's that old saying ....... horsepower sells cars, but torque wins races.
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From: Taylor Michigan
Very generous estimate at 460. The 454 LS7 was or is factory rated at the same 460 with several more good components than your proposed changes. Also a L72 is rated at either 425 or 450 depending on it`s build date. A very good image to follow in building a BB would be a L72`s. .......
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Le Mans Master
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From: Lebanon Township New Jersey
You won't like this but, by today's standards your starting HP is actually at least 10% lower than the factory rating because that rating, in 1968, was gross rather than net which has been used since 1971 or so. Your engine, by "net" standards would probably be rated around 350 HP to start with. Your mods might have added a little. Why don't you dyno the car or make a few passes at a drag strip to see for sure. (Car weight comparde to drag strip MPH can be converted to approximate, net HP.)
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Drifting
Joined: Apr 2007
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From: Springfield Illinois
I was thinking around 460 - 475 which still might be conservative. I think you huge upside will be on torque. However, with some head work and undercut valves, I think well 500+ HP is no doubt easily achievable.
I disagree with your first statement, but I agree with the last. Chevrolet was known for under rating their engines. Your best bet is taking it to the track and/or taking it to a dyno.
You won't like this but, by today's standards your starting HP is actually at least 10% lower than the factory rating because that rating, in 1968, was gross rather than net which has been used since 1971 or so. Your engine, by "net" standards would probably be rated around 350 HP to start with. Your mods might have added a little. Why don't you dyno the car or make a few passes at a drag strip to see for sure. (Car weight comparde to drag strip MPH can be converted to approximate, net HP.)
Last edited by FRSTR90; Aug 13, 2007 at 11:17 PM.
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From: Baton Rouge LA
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From: FL
I just figured that since I started at 390, which I have heard its really underated by GM and is closer to 400/410. Then adding the Torker II which is much different than the stock intake and the BG Holley which has to flow better than the stock QJ, and the sidepipes I would guess:
Stock 390/400 HP
Torker 20 HP
Holley 20 HP
Pipes 20
Atleast 460HP????
Stock 390/400 HP
Torker 20 HP
Holley 20 HP
Pipes 20
Atleast 460HP????
This is how ricers add up HP. Parts are not necessarily cumulative. I have to say that 400 gross is probably about all you have.
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Thanks for the brotherly kick in the ***.. Next time pass up my thread..
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From: Hastings MN
But yes, get it dynoed. I want to see what it actually is, and then I want to steal your car!
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He's not really being an AH, but just honest. Horsepower isn't going to stack up like that, and like everyone else has said, gross, net and rwhp are three very different things.
But yes, get it dynoed. I want to see what it actually is, and then I want to steal your car!
But yes, get it dynoed. I want to see what it actually is, and then I want to steal your car!
Im just tired of it.. I will dyno and post though. Thanks..
Melting Slicks
Joined: Aug 2005
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From: Lincoln CA
Actually, he beat me to the same comment. You just can't add up the mods to get the new hp rating. Some of those mods might add 20 hp to a stock engine stand alone but, in conjunction with the other mods, might not have nearly an additive impact. I have a 427/390hp car too, and I can tell you that my good old seat of the pants dyno tells me that there isn't any 390 hp coming out of that thing. My 2000 Z28 LS1 would clobber it in a heads up drag race and it's rated at 305 fwhp (Chevy was still at it in 2000 since my Z pulled 318 rwhp in nearly stock form on a dyno). The 427 seems to have a lot of power up top but just isn't that impressive out of the hole. I have to admit that the P.O.s mechanic replaced the original cam with a 396 cam of unknown specifications and that might contribute to the mild performance, but I've seen road tests from back in the day and the L36 setup ran low 15's in the low 90's in the quarter mile. That's not anything like 390 fwhp. Even my 302 powered 69 Mustang feels snappier out of the hole. The Vette might (stressing might) be able to run it down in the quarter, but I doubt it. The Mustang runs 14.30's @ 99 mph.
Last edited by RagTop69; Aug 14, 2007 at 06:48 PM.
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Actually, he beat me to the same comment. You just can't add up the mods to get the new hp rating. Some of those mods might add 20 hp to a stock engine stand alone but, in conjunction with the other mods, might not have nearly an additive impact. I have a 427/390hp car too, and I can tell you that my good old seat of the pants dyno tells me that there isn't any 390 hp coming out of that thing. My 2000 Z28 LS1 would clobber it in a heads up drag race and it's rated at 305 fwhp (Chevy was still at it in 2000 since my Z pulled 318 rwhp in nearly stock form on a dyno). The 427 seems to have a lot of power up top but just isn't that impressive out of the hole. I've seen road tests from back in the day and the L36 setup ran low 15's in the low 90's in the quarter mile. That's not anything like 390 fwhp. Even my 302 powered 69 Mustang feels snappier out of the hole. The Vette might (stressing might) be able to run it down in the quarter, but I doubt it. The Mustang runs 14.30's @ 99 mph.