What kinda power will i have? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Imacarguytoo · 11-07-2008, 05:19 PM

Hi guys. Im starting to build another motor. Heres the specs so far
350 bored 30 with stock pistons
stock 76cc heads
280 duration 480 lift in/ex Cam
Performer Rpm intake with holley 600 dualfeed mech sec.

Also all the same above but with 275 dome pistons.

Can anyone give me some HP levels please I will also be running a 4 speed

ripdog28 · 11-07-2008, 10:01 PM

I would guess low 300s. heads are holding you back. Get some Vortech and will be mid to high 300s

Marv D · 11-08-2008, 12:04 PM

Agreed, heads are where the power is made, and even in the best form, GM never produced a set of stock heads that would take a 350 above a 370HP rating (with 11:1 compression the best LT1 heads, mechanical cam.. and that HP was rated BEFORE the accessories were added to the motor). But don'tr despair,, 300 HONEST HP is quite respectable on the street.
Be carefull with the domes,, a 11cc dome in a 350 with 76cc somgger heads will put you just under 11:1 (10.87 to be exact) if you zero deck and use a typical builders head gasket. If you mill the heads any you could be jumping over 11:1 quite easily. Typically 0.008" per cc flat milling, a 0.030" cut makes your 76cc heads looses you about 4cc and puts compression the same combination at 11.4:1. See how quickly things gets out of hand. Be cautious and SURE of what your putting together.

thirdstreettito · 11-09-2008, 02:09 AM

Yeah get some heads man!

BarryB · 11-09-2008, 12:22 PM

This is what I had, a .030 bored over 350/ 350 crank ands rods. worked over set of 041 heads. Ported, polished and shaved. 2.02 swirl polished valves. Comp 480 lift, 280 duration cam. Weind excellator intake and a 600 cfm carb. when dynoed, it put out 434.? H.P. I don't remeber the torque. Been a while ago. But the same block is waiting on me to put it back together as a stroker.

Marv D · 11-09-2008, 11:20 PM

Quote:

Originally Posted by BarryB

This is what I had, a .030 bored over 350/ 350 crank ands rods. worked over set of 041 heads. Ported, polished and shaved. 2.02 swirl polished valves. Comp 480 lift, 280 duration cam. Weind excellator intake and a 600 cfm carb. when dynoed, it put out 434.? H.P. I don't remeber the torque. Been a while ago. But the same block is waiting on me to put it back together as a stroker.

Wow, I can't help but believe that was a very generous dyno. Not saying it's not possible, but over 400HP with that pcakage, and on a 600cfm carb, with no N2o is pretty much unheard of. Great job on that motor!!!!!

BarryB · 11-10-2008, 01:28 AM

Quote:

Originally Posted by Marv D

Wow, I can't help but believe that was a very generous dyno. Not saying it's not possible, but over 400HP with that pcakage, and on a 600cfm carb, with no N2o is pretty much unheard of. Great job on that motor!!!!!

Maybe I just got lucky. Possibly the dyno was miscalculated, But one thing I do know 100% is when I dropped it in the car (74 Nova), it was one scary ride. let's just say, I needed rear tires quite often

. I gotta tell you this, I let a friend of mine take it for a spin around the block. When he got back he was weak kneed.

. I wish I had pictures. I'd post them up of it. and the dyno slip. but I have moved twice since then.

Imacarguytoo · 11-14-2008, 09:34 AM

Summit Racing told me with the 275 domes i will have 10.1 in that motor. with stock heads. I have decided i am going to keep the bottom end stock for now, you know money issues lol. Atleast i will be around 300.

11-07-2008, 05:19 PM	#1
Imacarguytoo Registered User Join Date: Nov 2006 Location: Illinois Posts: 306	What kinda power will i have? Hi guys. Im starting to build another motor. Heres the specs so far 350 bored 30 with stock pistons stock 76cc heads 280 duration 480 lift in/ex Cam Performer Rpm intake with holley 600 dualfeed mech sec. Also all the same above but with 275 dome pistons. Can anyone give me some HP levels please I will also be running a 4 speed __________________ '67 C20 Lwb 350 4-Speed '01 Chrysler Concorde LXI (wifes ride) '91 Gmc Suburban 3/4 2wd 454 Tbi '51 Jeep Cj3a "Willys" 350 V8

11-07-2008, 10:01 PM	#2
ripdog28 Registered User Join Date: Apr 2008 Location: Imperial Beach, CA Posts: 1,040	Re: What kinda power will i have? I would guess low 300s. heads are holding you back. Get some Vortech and will be mid to high 300s __________________ 69 c-10 BBC 462ci, forged crank, H-beam rods, 10.5-1 KB forged pistons, Dart Iron Eagle 308cc, Straub Cam, Comp Cams chrome moly full rollers, Weiand Team G, Prosystems 950, TH400/3500 Dalenzie stall, Currie 9+ Detroit Locker w/31spline axles.3.5/6in drop. My Build.

11-08-2008, 12:04 PM	#3
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: What kinda power will i have? Agreed, heads are where the power is made, and even in the best form, GM never produced a set of stock heads that would take a 350 above a 370HP rating (with 11:1 compression the best LT1 heads, mechanical cam.. and that HP was rated BEFORE the accessories were added to the motor). But don'tr despair,, 300 HONEST HP is quite respectable on the street. Be carefull with the domes,, a 11cc dome in a 350 with 76cc somgger heads will put you just under 11:1 (10.87 to be exact) if you zero deck and use a typical builders head gasket. If you mill the heads any you could be jumping over 11:1 quite easily. Typically 0.008" per cc flat milling, a 0.030" cut makes your 76cc heads looses you about 4cc and puts compression the same combination at 11.4:1. See how quickly things gets out of hand. Be cautious and SURE of what your putting together. __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

11-09-2008, 02:09 AM	#4
thirdstreettito Resident of Here Join Date: May 2008 Location: Wesley Chapel, FL, USA Posts: 7,716	Re: What kinda power will i have? Yeah get some heads man! __________________ ~Bradley~ 2004 Black GTO LS2/T56 too much to list Miss having a truck

11-09-2008, 12:22 PM	#5
BarryB Senior Member Join Date: Jul 2006 Location: Blountville, Tn. Posts: 3,904	Re: What kinda power will i have? This is what I had, a .030 bored over 350/ 350 crank ands rods. worked over set of 041 heads. Ported, polished and shaved. 2.02 swirl polished valves. Comp 480 lift, 280 duration cam. Weind excellator intake and a 600 cfm carb. when dynoed, it put out 434.? H.P. I don't remeber the torque. Been a while ago. But the same block is waiting on me to put it back together as a stroker. __________________ We could learn a lot from crayons... Some are sharp; some are pretty;and some are dull. Some have weird names; and all are different colours;but they all have to live in the same box. You may be only one person in the world, But you may also be the world to one person. * Some mistakes are too much fun to only make once. Two rules in life. 1. Never sweat the small stuff! 2. Everything is small stuff!

11-14-2008, 09:34 AM	#8
Imacarguytoo Registered User Join Date: Nov 2006 Location: Illinois Posts: 306	Re: What kinda power will i have? Summit Racing told me with the 275 domes i will have 10.1 in that motor. with stock heads. I have decided i am going to keep the bottom end stock for now, you know money issues lol. Atleast i will be around 300. __________________ '67 C20 Lwb 350 4-Speed '01 Chrysler Concorde LXI (wifes ride) '91 Gmc Suburban 3/4 2wd 454 Tbi '51 Jeep Cj3a "Willys" 350 V8



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