Keep my heads or change them?
Thread Starter
Instructor
Joined: Dec 2002
Posts: 117
Likes: 0
From: Haddon Heights NJ
Keep my heads or change them?
I'm gettin ready to tear down the top end this weekend as all my parts have come in. Performer intake, xe268 comp cam, march pulleys, etc. Now after thinking about this i'm not sure about the heads. Its not the original motor. The heads are 487's 76cc combustion, 161cc intake and 65cc exhaust with 1.94/11.50 valves(according to mortec) My question is should i go to a 64cc head? I saw these in ebay but not sure if there worth it. Don't want to get done and be disappointed because i didn't change em, but not sure if its worth changing them. Any help would be great
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEBWA%3AIT
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEBWA%3AIT
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Re: Keep my heads or change them? (Mikeb690)
'487 and '487X are just about the only GM cast iron 76cc heads that are actually worth keeping, IMO.
It just depends on how you want to use the car. Street cruiser? No problemo.
It just depends on how you want to use the car. Street cruiser? No problemo.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
Re: Keep my heads or change them? (Mikeb690)
The 64cc heads sound like a bargain. I wonder what casting number they are? I'd also verify the compression ratio you are starting with. Anything over 8.5:1 will mean you are looking at close to 9.7 (.4 CR for every 4 CCs difference I recall) with the 64cc heads; at the limit for cast iron on premium fuel.
Melting Slicks
Joined: Aug 2003
Posts: 3,415
Likes: 291
From: dayton oh
Re: Keep my heads or change them? (Mikeb690)
You'd also have to get a different intake. That Performer won't mate up to the Vortec heads !!!!!!!!!!!!!!!!
[Modified by Fast81, 2:48 PM 4/28/2004]
[Modified by Fast81, 2:48 PM 4/28/2004]
Thread Starter
Instructor
Joined: Dec 2002
Posts: 117
Likes: 0
From: Haddon Heights NJ
Re: Keep my heads or change them? (Fast81)
You'd also have to get a different intake. That Performer won't mate up to the Vortec heads !!!!!!!!!!!!!!!!
[Modified by Fast81, 2:48 PM 4/28/2004]
[Modified by Fast81, 2:48 PM 4/28/2004]
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Re: Keep my heads or change them? (Mikeb690)
Then I'd take the $$$ you'd spend on the eBay heads and give yours a good valve job, skim 'em flat and be happy. You can't hardly go wrong with the '487s.
Drifting
Joined: Nov 2002
Posts: 1,665
Likes: 1
From: Ontario
Re: Keep my heads or change them? (Mikeb690)
Good head comparison page...
http://www.chevytalk.com/tech/engine/SBC_Heads.html
Speed costs money how fast do you want to go? :cheers:
http://www.chevytalk.com/tech/engine/SBC_Heads.html
Speed costs money how fast do you want to go? :cheers:
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Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Keep my heads or change them? (Mikeb690)
Do you know your current compression ratio? A set of used alum vette heads would give you a nice bump in compression. they are not the best flowing heads but if you are looking at under 400 hp you would be hard pressed to beat em for the price.
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Re: Keep my heads or change them? (Mikeb690)
When I built my engine, I put a lot of bux into cast iron heads. I got new Stainless valves, Crane roller rockers, screw in studs etc but the money would have been much better spent on aluminum. I'm running close to 10:1 and she Does Ping when hot.
Someday I'll find a good deal on some aluminum heads but for now I really need to watch what I do.
:nonod:
Someday I'll find a good deal on some aluminum heads but for now I really need to watch what I do.
:nonod:
Instructor
Joined: Jun 2003
Posts: 183
Likes: 0
From: Gordonville MO
Re: Keep my heads or change them? (SanDiegoPaul)
From quite a bit of research and tests I've read, you'd see a
substantial gain from Vortec heads over those on ebay.
Better port velocity, more detonation resistance, better swirl.
Check ebay, there's usually some there with ss valves,
better springs and seals, and guides modified, so you can
run somewhat over .500 lift - varies depending on who's
doing the heads. Better deal than totally stockers which
are lift limited to about .450. Best are ones with
30 deg added back cut on the exhaust valves.
http://www.corvettefaq.com/c3/goodwr...20part%201.htm http://www.chevyhiperformance.com/techarticles/76178/ http://ryanscarpage.50megs.com/combos2.html
On the last one, scroll thru all the pages. Pay attention
to how much better similar motors did with the Vortec
heads over the other, older tech Chev hi perf heads.
Check out a couple 350 combo's with the same cam
etc as you're planning, with Vortecs and the right intake
they make amazing power on a budget.
Good luck!
substantial gain from Vortec heads over those on ebay.
Better port velocity, more detonation resistance, better swirl.
Check ebay, there's usually some there with ss valves,
better springs and seals, and guides modified, so you can
run somewhat over .500 lift - varies depending on who's
doing the heads. Better deal than totally stockers which
are lift limited to about .450. Best are ones with
30 deg added back cut on the exhaust valves.
http://www.corvettefaq.com/c3/goodwr...20part%201.htm http://www.chevyhiperformance.com/techarticles/76178/ http://ryanscarpage.50megs.com/combos2.html
On the last one, scroll thru all the pages. Pay attention
to how much better similar motors did with the Vortec
heads over the other, older tech Chev hi perf heads.
Check out a couple 350 combo's with the same cam
etc as you're planning, with Vortecs and the right intake
they make amazing power on a budget.
Good luck!
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: Keep my heads or change them? (Mikeb690)
I'm gettin ready to tear down the top end this weekend as all my parts have come in. Performer intake, xe268 comp cam, march pulleys, etc. Now after thinking about this i'm not sure about the heads. Its not the original motor. The heads are 487's 76cc combustion, 161cc intake and 65cc exhaust with 1.94/11.50 valves(according to mortec) My question is should i go to a 64cc head? I saw these in ebay but not sure if there worth it. Don't want to get done and be disappointed because i didn't change em, but not sure if its worth changing them. Any help would be great
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEBWA%3AIT
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEBWA%3AIT
Good luck. cardo0
[Modified by cardo0, 9:40 PM 5/1/2004]
Instructor
Joined: Apr 2002
Posts: 223
Likes: 0
From: Spokane Wa
Re: Keep my heads or change them? (Mikeb690)
You will be very happy with heads you have if you port and polish them. Don't forget to pocket port behind the valve and clean up the runner just above the valves. The factory added a lot of extra metal here. Do a valve job- Stay with the same size valves. Going bigger is not always the way to go. On the street a good flowing tork building head will give you that seat in the pants feeling and save you some big bucks. Larger heads move more air. But at a lot higher RPM range. That means you need a bigger cam,intake,gears,ETC. On the street most cars run up to 5000 RPMS. The smaller heads will agian and agian prove to work in this range. Good luck. :steering:
2nd Gear
Joined: May 2004
Posts: 2
Likes: 0
From: Berwick Pa
Re: Keep my heads or change them? (fnseeker)
I had my 75 coupe 350 redone into a 383. Andy Jensen of Nescopeck, Pa did all the work. He used my stock heads opened them up to 2.02 and 1.60 valves he reworked the heads. He said to save the money from Aluminum heads that he could get stock heads to work just as well. It cost around $400 or $500 I dont remember. He has the fastest street legal 65 Corvette with a 472 Small block runs mid 6's. Check him out does super work.
ACE :chevy
ACE :chevy
