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Discussion Starter · #1 ·
Aluminum or Iron? Dart II, Iron Eagle, Edelbrock, World, Trick Flow, etc., stock? If stock GM, which ones? It's a '73 and they didn't have hardened valve seats so they'll need to cut/install all them at least, one valve is totally toast and I think a couple more aren't doing so hot; guides have 28 years and 280K miles, etc. I think replacement might be better than rebuild in this case? Right now it has 10:1, and an Isky 292/505 cam; Edelbrock Performer with Q-jet, headers and 54" long 2-3/4" glasspacks. Power estimates? What can I expect to get out of this beast with good heads?
 

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If you have the $$$ go with Darts or Trick Flow. Bolt on HP! If you have some skills it not to hard to port and polish stock heads. You can also match the intake and exhaust ports to the gaskets, allowing a unrestricted flow.
 

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With the added stroke go for a head and intake that flows more than you think you need. Get a good flowing head with say a Torker II intake not some performer RPM.
 

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I used some "69 vette 202/160" heads on my 383 and "tricked" them out. They seem to "flow" just fine...
<IMG SRC="smilies/smokin.gif" border="0"> <IMG SRC="smilies/tongue.gif" border="0"> <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/beer.gif" border="0">
 

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The thing is to make them flow or you are realy cutting off the potential of the motor. My opinion is give up some lowend torque I.E. high flow intake/heads/exhaust to gain a better spread of power. So don't put things on that are designed to work on a 350 up to 5000 because it will fall on its face much sooner on a 383. Within reason of course.
 

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If I was you I would install the vortex GM heads. They go for around $230 each. I think if you go with a larger head you will have a lot of trouble with off the line preformance. I see the cam that you are going to use is pretty large if you are using it for 4 wheeling. It all depends on what you are doing with it. For 4 wheeling I would use nothing more than a cam up to around 270 advertized duration and the vortex heads. It doesn't matter how much the head flow it is the velocity in the head that will help the most. Even if your heads flows 300 cfm more than likely your manifold will only flow 240 cfm. So why bother with that. Here is a link to a place to estimate the cam for you. It cost $35 but I believe it will be well worth it to you. http://www.davidvizard.com/camshaft.html
 

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I hear the stock Vortec heads flow very well. Probably nearly as well as some custom heads.

For the price, I'd go with Vortec.

Charles
 

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AFR (AKA Air Flow Research) <IMG SRC="smilies/thefinger.gif" border="0"> I say go with a steel head. if you hit water on a hot alum head it will crack like a 757 hitting a skyscraper... A good factory head in a 4x4 cant be beat.
 

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Discussion Starter · #10 ·
I appreciate the link to the cam selection software; I'll probably try that, but this cam came already installed in the engine. Of course since the heads have gotta come off anyway it's not that more work to change, but not sure that I want to - at least yet. Yes it lacks some low-end grunt and is almost certainly not the one I would have picked, but it is in there, actually idles OK (although a bit rough) after I donked with the carb a little, but just flat gets it above 2K rpm. <IMG SRC="smilies/biggrin.gif" border="0"> I think because it is a larger displacement, a larger cam is not as detrimental to general driveability as the same cam in a smaller engine would be. My daily has a 350 Vortec in it and I like it - but isn't the intake flange pattern different? I like the 'vette heads too, but not sure about when they started putting hardened valve seats in 'em. I'll see what kind of a deal I can scare up in the yards, maybe some of the shops have some worked over they'd trade me for. Maybe Iron Eagles... Thanks for the input!
 

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Lloyd,

I found some Vortec heads in Jeg's catalog that are made to go on the older Chevy blocks (the ones without the centerbolt heads).

Charles
 

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Discussion Starter · #12 ·
Originally posted by fj40charles:
<STRONG>Lloyd,

I found some Vortec heads in Jeg's catalog that are made to go on the older Chevy blocks (the ones without the centerbolt heads).

Charles</STRONG>
Cool, this sounds like just what I'm after. That, and a bunch of new stuff for my die grinder... <IMG SRC="smilies/biggrin.gif" border="0"> THANKS! <IMG SRC="smilies/smile.gif" border="0">
 

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Are you building a race motor...or a crawl motor that should perform from off idle to 3500 RPMs....... <IMG SRC="smilies/trooper.gif" border="0">
 

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Discussion Starter · #14 ·
Originally posted by Fabricator:
<STRONG>Are you building a race motor...or a crawl motor that should perform from off idle to 3500 RPMs....... <IMG SRC="smilies/trooper.gif" border="0"></STRONG>
Neither. It's really a general-purpose sort of thing. Some crawling, some mud, some pounding through the desert, some sand, etc. With the altitude at home (8200 ft.) it'll run on regular unleaded at 10:1, and if I go to Albuquerque (ca. 5600) it'll be ok on 91 octane. A friend of mine used to have a 402 with the factory aluminum heads (11:1) and he could run it at sea level with a gallon of diesel per tank of gas, so I'm not concerned about the compression it's at now, but don't really want to go much higher - if anything maybe down half a point.
 

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Aluminum heads run so much cooler that they alow you to run up to 1/2 more on the compression before it pings. I think the Vortec heads are a good choice.
 

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In my 383 with 6" rods and 10:1 I'm running the Trick Flow Twisted Wedge G2 Aluminum heads and have been real pleased with them.

I know a person that does heads for racing here was very impressed with them.
 

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Discussion Starter · #17 ·
Thanks guys - always good to get more data, especially from someone with the same basic engine. I really like the ideas that have gone into some of the newer aftermarket heads, and think that it'll help on this one. Not so sure that I like the price of some of them, but good things are seldom cheap.
 

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I would go Vortec heads. Outflow majority of aftermarket heads in the cheaper price range (if you want to now how GM has the $$$$$$) also they have smaller ports and valves to still get good low range. Edelbrok makes the apropriate intakes to go with these heads
 

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Llyod I have another cam site for you to look at. http://www.elgincams.com/campaper.html
This company does 90% of the cams for NASCAR but nobody will tell you this. We have ordered a cam from them for a Caddy 500 engine and they have really took the time to get this thing right. We should have it in a week or two. I would diffenently stick with the 10-1 compression for you altitude. I live in Denver and I know how bad the altitude kills your engine.
 
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