Vortec worth it??
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Joined: Mar 2005
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From: Baytown Texas
Vortec worth it??
First of all, I have a 77 vette with a stock 350...and i have recently decided to do some work on it. I figure I can get a brand new set of Vortec heads..a nice cam and a Vortec intake for around $1000-ish..and soon enough work on the exhaust with some nice headers... Can anyone help with what kind of horsepower I might pick up with this set up.. Oh..and i heard this set-up might not fit with the stock hood...so would i have to fork out some cash for a new hood also? 
Melting Slicks
Joined: Jan 2004
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From: New Cumberland PA
Essentially what you are doing by changing the topend and the exhaust is going back in time when horsepower was 300+. I would hope that your plans are to change to true duals as well. Depending on which cam you choose, the engine should be capable of making more ponies than the 350ci/350hp did in the early days.
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From: Baytown Texas
I appreciate the help..if there is anyone who actually did this installation already..could you inform me about any problems that arose from doing this..sort of give me an early warning about possible problems.....thanx
Melting Slicks
Joined: Dec 2000
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From: Eastern Connecticut
The one thing missing from the vortec heads is the exhaust crossover that heats the choke. You will have to convert to electric choke. Not a big problem, the late model choke element will work in your housing, I think. Joe
Instructor
Joined: Jan 2005
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From: West Seneca New York
Make sure you upgrade the valve springs and put screw in rocker arm studs if your going to run a cam with more than .480 lift.
I put a LT4 Hotcam w/1.6 roller rockers in mine. .525 gross lift. Dyno'ed out so far at 348 hp/378 ft.lbs. Numbers will be higher next time around once we get the jetting right.
Darryl
I put a LT4 Hotcam w/1.6 roller rockers in mine. .525 gross lift. Dyno'ed out so far at 348 hp/378 ft.lbs. Numbers will be higher next time around once we get the jetting right.
Darryl
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Joined: Mar 2005
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From: Baytown Texas
Thanx for the heads up Darryl..but what kind of carb r u using with that setup? I heard from a guy at work who builds engines that Demon Carbs are good for the price..and im sort of on a budget here. I had never heard of them before this..can anyone provide info on reliability, performance, etc...
Le Mans Master
Joined: Mar 2002
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From: Coming home from Luckenbach Texas
I'm gonna do a 180 on ya here...
Go with the Summit-labeled Dart Iron Eagle heads. SUM-152123 They have a Vortec-style combustion chamber, and you can use your original manifold (if you want). No special manifold required. I'd recommend keeping the QJet -- it's a better carb than most people think.
These heads are good for about .520 lift (much more than stock Vortecs), so you can add a nice lumpy cam. Good midrange power. I installed a set, and they rock!
Go with the Summit-labeled Dart Iron Eagle heads. SUM-152123 They have a Vortec-style combustion chamber, and you can use your original manifold (if you want). No special manifold required. I'd recommend keeping the QJet -- it's a better carb than most people think.
These heads are good for about .520 lift (much more than stock Vortecs), so you can add a nice lumpy cam. Good midrange power. I installed a set, and they rock!
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From: Baytown Texas
I have actually read quite a bit about those heads on this forum..seems that have a pretty good reputation with C3 owners...i will definately look into those. But the main reason I was asking about carbs was because my original carb was all junked out when my uncle gave me my Vette...so i have no choice but to buy another..i have had it rebuilt twice and it still isnt up to par... So i just didnt know what was better for the price.. Is anyone here selling a good condition Carb..i know this probably isnt the right forum..but i was just asking..
Thanx again to everyone who has helped me out..im still trying to learn all i can about my car..turning into the love of my life..haha
Thanx again to everyone who has helped me out..im still trying to learn all i can about my car..turning into the love of my life..haha
Last edited by C3Curves; Apr 2, 2005 at 08:08 PM. Reason: just giving proper thanx
Melting Slicks
Joined: Oct 1999
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From: Tolar Texas
Vortech heads decision guide.
The information provided in this link might help you to make an informed decision.
http://www.2quicknovas.com/vortecheads.html
http://www.2quicknovas.com/vortecheads.html
Le Mans Master
Joined: May 2002
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From: Lebanon Township New Jersey
One other minor item when using Vortec heads is that your temperature sender will have to be relocated to the intake manifold, near the thermostat housing. I used an Edelbrock Performer and reused the stock sending unit. You have to extend the wire a few inches.
Racer
Joined: Feb 2001
Posts: 405
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From: Minneapolis
I considered doing the same thing to my '79, but decided that it required too much "engineering" to make it work. For example, do you have factory air? IF so, do you have a strut going from the AC compressor to one of the intake bolts? If so, the Vortec won't work,without doing some machining to make a provision for it.
I did a $$ estimate and found that it was cheaper to go with World Heads, stock intake, and original valve covers. Air cleaner on my '79 would also have been a prob. Glad it's not a factor on '77's.
I think the HP is pretty comparable both ways.
My $.02
I did a $$ estimate and found that it was cheaper to go with World Heads, stock intake, and original valve covers. Air cleaner on my '79 would also have been a prob. Glad it's not a factor on '77's.
I think the HP is pretty comparable both ways.
My $.02
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Joined: Mar 2005
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From: Baytown Texas
thanx..didnt know that..but i dont have the a/c working anyway. I have been thinking that i would just rather keep the compressor off for now, even though i do live in Southeast Texas..where humidity is worse than the heat...Dunno about that one yet..heh 
Melting Slicks
Joined: Jul 1999
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From: White Pine / Dandridge TN
I've been running vortec heads for nearly 5 years and really enjoy them. I'm running with a Carter 625 cfm carb. As far as using the stock temp sender and mounting the a/c compressor, I had no problems. Found an adapter at the hardware store for the temp sender for $1.00. The only modification I had to make to mount the a/c compressor was to buy a different stud from the dealership for about $5.00. Otherwise, no other modifications other than the vortec intake manifold. In my case I needed to purchase a new intake anyways.
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From: Baytown Texas
Speaking of carbs, when I try to take my vette on the highway, it tends to bog down around 50-60 mph...not completely sure..speedo cable has to be replaced. I figured this is due to the Carb?? Any other possibilities?? If so i think i am going to go ahead and buy another Q-jet..i cannot remember off the top of my head how much CFM the stock carb is..any help?
Melting Slicks
Joined: Jan 2004
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From: St. Petersburg, Fl///Columbus, Ohio
I built an iron head ZZ4 engine topped off with an elderbrock carb from autozone for @$300.00... I had to go richer on the jets & change to an electric Choke but I LOVE IT!!!!! I should be WELL over 350 hp... and my numbers matching engine is on a stand in my garage....unharmed.
YES i had to drill & tap a hole for the Z-bar ball... 1/2 hour, YES i had to buy a new flywheel for the Vortec crank, Yes I had to cut the head off 1 timing cover bolt to use the "short" waterpump, Yes I had to re-locate the coolant temp sensor... and YES I'd do it again!!!! My a/c & p/s brackets bolted right up. by the math my hp should be close to 400hp & I've got a completely new engine that doesn't leak & won't harm the value of my car if it blows!!!!!
YES i had to drill & tap a hole for the Z-bar ball... 1/2 hour, YES i had to buy a new flywheel for the Vortec crank, Yes I had to cut the head off 1 timing cover bolt to use the "short" waterpump, Yes I had to re-locate the coolant temp sensor... and YES I'd do it again!!!! My a/c & p/s brackets bolted right up. by the math my hp should be close to 400hp & I've got a completely new engine that doesn't leak & won't harm the value of my car if it blows!!!!!
Last edited by jcswm; Apr 3, 2005 at 12:17 AM.
i have trouble even saying it...
Le Mans Master
Joined: Mar 2002
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From: Coming home from Luckenbach Texas
Originally Posted by C3Curves
Speaking of carbs, when I try to take my vette on the highway, it tends to bog down around 50-60 mph...not completely sure..speedo cable has to be replaced. I figured this is due to the Carb?? Any other possibilities?? If so i think i am going to go ahead and buy another Q-jet..i cannot remember off the top of my head how much CFM the stock carb is..any help?
I'd suggest dropping a note to Lars describing your carb problem. Perhaps he can suggest a fix. You shouldn't have to buy another carb unless the one you have is TOTALLY trashed...