73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: SUX2BU99 on July 11, 2007, 03:13:47 pm
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Sorry to keep revisiting this stuff, but I want to make sure I make a well-informed decision on purchasing these not-so-cheap components and I respect your guys opinion.
So I was ready to buy a set of new factory Vortec heads. $550-ish + shipping depending on where you look for a pair. Upside is best bang for buck for a factory head. Downside is needing a different intake manifold, rockers and the stock valve springs only allow 0.475" of lift. 170cc intake runner volume, 64cc chamber.
Well, I was actually ready to first buy a cam and to accmodate the heads I decided on a Comp Cams Xtreme Energy 262 duration cam, because it fit under the max lift of the stock valve springs. I originally wanted an Xtreme Energy 268 cam.
Then I was poking around for comparisons and saw an ad for Aerohead heads. $625 and you get a larger 72cc chamber to be a little more detonation friendly and a smaller 165 cc intake runner volume. These are actually Dart Iron Eagle S/S heads. Same size valves as the Vortecs (1.94/1.50)
Now on paper, these don't look too special but I found a GREAT article that I've linked to below. It's a shootout with Scoggin-Dickey modified Vortecs ($680) and the Aeroheads plus some others on a mild 383 with an Xtreme Energy 274 cam. The Aeroheads made about the same power as the Vortecs (a little less), which is expected considering the smaller runner volume and bigger chamber. The Vortecs though had to be modified in order to use that cam and cost $55 more than the Aeroheads.
http://www.chevyhiperformance.com/tech/engines_drivetrain/cams_heads_valvetrain/0606ch_cylinder_head_performance_test/aerohead_racing.html
So considering the fact that I'd have to use a 262 cam with stock Vortecs and after buying new rockers, a new intake, and selling my existing intake, I'd be about $75 in the hole and maybe down 15-20 HP vs. buying the Aeroheads, using the billet roller rockers I have now and the Performer intake I already have along with a 268 cam.
Considering all this, what do you think?
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All the buzz about the Vortech heads is you can get them used for close to nothing and they perform well. I got my last set for free. Buying them new and changing everything you have is kind of a waste of $ if you are on a budget. So being that you are on a budget why not just find a decent set of GM castings and put the correct springs for your cam, port them and get them to perform for you. Or splurge a little and get a nice set of aluminum heads and keep your compression ratio higher.
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I agree with Zambonie there are tons of 76cc 882 heads out there that can be refurbished cheaper than either of those options.
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Thanks for the feedback. If I can get a set of used Vortecs that don't need $200+ in work done to them, for cheap, yeah that would be a great way to go. Buying them new though, seems to not be as financally advantageous as I originally thought since I found the Aerohead/Darts.
Maybe I have some more investigation to do. I've seen some freshly pulled Vortecs complete wtih stock rockers on Ebay for $200-ish. But how much does a shop charge to check them out? Or to replace springs? I don't know any mechanics well enough to really be confident in abilities or accurate pricing. I could take a set of pulled heads to a guy and have him change the springs only to get nailed hundreds of dollars for all new everything plus machining. And then try not to worry that his work on something crucial like a valvetrain is reliable. I'm sure most any place will put on some hard pressure to rebuild any used head that comes into their shop.
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So I found out from a local shop that to rebuild a set of non-cracked Vortec heads would be $350 EACH :o Ouch. So my only 2 options I think I'll consider is using a set of pulled Vortec heads as-is or cough up for the Darts. It would be about a $225 difference. Something to think on, but then I'd have new Darts vs. used Vortecs that are not rebuilt.
A friend suggested I look to see what kind of heads I have now, so I pulled a valve cover last night. The last 3 digits appear to say 336 on the casting number. I also have stamped roller-tip rockers; I thought they were billet when I changed the valve covers a couple years ago. Oh well. So are the 336's anything decent?
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I found the entire number on the Mortec site. This is what they say: 3986336....71......350..........76cc chamber
So any good? Keep? Sell? Toss?
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If you just want a set of good GM heads give Dover Cylinder head a call and ask for Jessie. See what he has for you... He's been really good to me over the years http://www.doverheads.com/
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Again, don't rule out the L98 corvette heads. I like these because they are 60LBS lighter than stock, not to mention the increased performance they bring. 60lbs may not sound like a whole lot in a 4000lbs truck but it's a start. Alum water pump, intake, lightweight starter etc. and you're starting to make some small performance gains without spending too much money.
But i think we can all agree that the best heads period for the SBC are the arao 32valves:
http://www.araoengineering.com/Chevy/chevysmb.htm
So, those are actually the heads that i want you to get. If those are not within the budget then this is what i would personally shoot for in order of preference:
1. L98 Corvette heads
2. L31 aluminum vortechs
3. L31 regular vortechs
4. Aftermarket heads such as Dart Sportsman 2/ Iron eagle etc.
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The 32 valve heads start a $8000 and would probably be good for a drag motor, but not for a street vehicle, and DEFINITLEY not for use with a 268 cam.
I would pick the heads based on the package you are planning on building. A 268 cam is slightly overstock, you won't be gaining much by putting HUGE port heads on it. It sounds like you are looking for something more daily driver oriented with a little pep, is this correct?
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Yep, you got it Chris. I want something with some grunt to it that's not so tempermental that I couldn't take it thru the rush hour crawl if I had to. I've seen a few combos similar to what I have now and what I have planned that make about 350 HP and that's right where I'd like to be. What I like about the 268 Xtreme cam so much is that I get the lift of a 272-ish size cam, or 280 duration, but with the lobe separation and duration that a 268 offers. That to me means more power with better driveability. I don't want my RPM range much beyond 5500 and I'll be keeping my stock converter. The nice thing about the Dart heads is they are small valve (1.94/1.50) and larger chamber.
I don't have a problem with the Vortech heads, or the L98 heads. It's just availability and cost. If at the end of the day I can use the 268 cam with Dart heads for same or less money as a set of stock Vortechs and a 262 cam (due to stock valve spring limitations of the Vortechs), then that's probably the better combo. To make the Vortechs advantageous, I'd have to use a used set as-is without a rebuild and that's kinda no good.
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Call Dover and ask them for a set of heads with performance springs. You can probably score a nice set for under $300 bucks. I got a set of 2.02 corvette heads with Lt1 springs for $250 for one of my customers.
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Wow, that's pretty good. I had look at their site after you mentioned it and I thought they were just stock head rebuilders, but if they have some factory performance heads, I'm game for that. What are some performance casting numbers to watch for?
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I think you'll really like that 268 cam if you go that route.. for a daily driver type,thats my all time favorite sbc cam..a little choppy idle,but still good low end power,breathes good at higher rpm,just a good all around cam.. I like the 280/480 in a 400/406,but it's a little rowdy in a daily driver 350,real soggy on the bottom end with stock gears and convertor..If you have a dragstrip nearby,find their website and check the classifieds,then if you find something you like,they'll be local..theres always good heads for sale on mine..vortechs, alum. corvette,world sportsman II's etc.. I seen some fresh vortechs sell the other day for $200
Tim
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Hey, that's a great tip, Tim. I do have a dragstrip in Mission BC, about 30 min. from where I live. I'll check their site. I'd like to find some local websites for V8 performance but haven't found any besides late model Camaros and Mustangs.
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So what's the deal with 'double-hump' heads not having accessory holes? I saw a pair for the first time in person last weekend and couldn't believe they had no holes at all. Various forms of these came in different cars during the 60's right? Did they use different brackets for alternator, air cond, power steering pump, etc? I thought GM mounted the alt. the same way in all their SBC-powered vehicles but there is no lower bolt in those heads for it to bolt to.
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The ones with no holes used different brackets for the alternator and such. It pretty much changed in 1970 if you want a marker of when the brackets changes.