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Old 04-27-2011, 12:08 AM
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No horsepower for my 70 Chevelle

Hey everyone, Thanks for letting me into your forum, one of my questions is about a sbc 350, I pulled out the stock 350 goodwrench engine, with about 260 hp and replaced it with a rebuilt 350, it has been bored to .030 and has a cam with 454 lift and Flat top pistons, and 194 heads and 76cc. This is how I recieved the block. The block casting # is 3970010 and the heads are casting #333882 and so far what I have read about these heads they are called smoggers and are not any good for creating horse power, I have installed a Eldebrock 2601 air gap intake and have a Carter 625 which I had on my goodwrench, also I have installed a new Mallory HEI distributor, anyone have any idea where I can start to backtrack and find out why I have less hp now than before changing engines. Thanks Kamutr

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Old 04-27-2011, 07:20 AM
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make'n HP

at first look at what u have i say your in the 250 to 300 hp.. nice stuff but not overly high end.. nice st engine.. the only thiing i see is the air gap.. i'm running one also and i had to close the gap between the planes to get it to run right.. its that gap just under the carb.. i bent a pc of sheet mtl over and crimped it and made a major diff....
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Old 04-27-2011, 07:40 AM
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swap out the heads for somthing that matches your budget.

low budget.....http://cgi.ebay.com/ebaymotors/ws/eB...51580126722599


medium budget......http://www.dartheads.com/products/cy...der-heads.html


no budget.........http://www.trickflow.com/egnsearch.a...5&autoview=sku

good heads are the #1 power maker on a small chev.


go with a smaller 58-64cc more efficient chamber design and you will see huge gains on your combo.

smogers are awfull in so many different ways.
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Old 04-27-2011, 08:26 AM
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I agree with mud bros. I would advise a 64 cc chamber like all the duble hump or the 492 angle plugs then angle milling to reduce to 58 cc . those 305 heads with 58 ccs arent what some think.
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Old 04-27-2011, 08:53 AM
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Quote:
Originally Posted by kamutr
Hey everyone, Thanks for letting me into your forum, one of my questions is about a sbc 350, I pulled out the stock 350 goodwrench engine, with about 260 hp and replaced it with a rebuilt 350, it has been bored to .030 and has a cam with 454 lift and Flat top pistons, and 194 heads and 76cc. This is how I recieved the block. The block casting # is 3970010 and the heads are casting #333882 and so far what I have read about these heads they are called smoggers and are not any good for creating horse power, I have installed a Eldebrock 2601 air gap intake and have a Carter 625 which I had on my goodwrench, also I have installed a new Mallory HEI distributor, anyone have any idea where I can start to backtrack and find out why I have less hp now than before changing engines. Thanks Kamutr
Other than the heads that are holding back power, you need to be sure the ignition advance curve is as aggressive as the engine will allow, w/o detonation.

Use as much as 14-16 initial (less if the starter struggles when the engine is hot, but at least 10-12).

Use 36-38 total timing, all in no later than 3000 RPM and sooner if you can w/o detonation.

Use a vacuum advance hooked to manifold vacuum to add another 10-12 under light throttle/cruise conditions and at idle.

You'll want to readjust the idle air/fuel mixture screws to give the highest vacuum at idle (or highest RPM). Reset the curb idle screw to keep the idle speed correct as you gain idle speed from the changes to the idle mixture screws and the vacuum advance can vacuum source (if you were using ported vacuum previously, the idle speed will increase when you hook it up to manifold vacuum).
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Old 04-27-2011, 09:10 AM
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No horsepower for my 70 Chevelle

When I got the paperwork from the engine rebuilder he said the 1.94 heads had a 68 cc and after looking up the head identification # 333882 it showed a 76 cc is it possible he had some work done to make this happen or is it most likely smoke out my tailpipes. Also I am looking into a set of 2.02/1.60 with 64cc. What intake runner do I look for. Thanks Kamutr.
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Old 04-27-2011, 09:31 AM
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Quote:
Originally Posted by kamutr
When I got the paperwork from the engine rebuilder he said the 1.94 heads had a 68 cc and after looking up the head identification # 333882 it showed a 76 cc is it possible he had some work done to make this happen or is it most likely smoke out my tailpipes. Also I am looking into a set of 2.02/1.60 with 64cc. What intake runner do I look for. Thanks Kamutr.
You want an intake port volume of around 170-180cc. You do not need 2.02 x 1.60" valve heads.

Does your engine have dished pistons? The best thing you could do for the least money is get a set of Vortec L31 5.7L truck heads, c/n 062 or 906. They flow real good and other than needing a specific intake manifold, they are a bolt on deal. I'd prolly upgrade the valve springs and be sure to use the self aligning rocker arms the heads come with.
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Old 04-27-2011, 10:15 AM
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the vortecs are the way to go, and like cobalt said you dont need 2.02's a set of 1.94's will serve just fine, (you lift isn't above .500") but i'm not the biggest fan of buying the old 906, 062 vortecs espcially if you're not experianced in looking for problems. plus then you have to have get higher lift springs and in many cases grind down the guides some. personally i would just buy a set of RHS pro torker 170cc heads, they have the bolt pattern for both the early style intakes and the vortec style intake, they already accept lifts up to about .525" and they also flow about 5% better than the original vortecs. for around 750.00-800.00 that aint bad (IMHO)
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Old 04-27-2011, 12:34 PM
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Go with some Vortecs, and get the GMPP .028 Head gaskets to tighten up your quench odds are you are .025 in the hole with cheap Felpro .041HGS and you have 9.2:1 with your 76CC heads even if they are milled.

Run Vortecs 670.00 Intake 150.00 and 2- GMpp .028 Gaskets 19.99 each at your GM dealer.

You'll have another 40HP and it will rev a lot smoother/
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