350 top end upgrade question
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350 top end upgrade question
I have a 350 from a 1973 Z28 setup with
- 3972116 intake (1970 LT-1 replacement part)
- camel hump heads (186)
- Hooker headers into 4" side pipes
- Edelbrock carb
Now I have the opportunity to get a set of :
- Performer RPM intake
- Edelbrock 6089 heads
I'm looking to get a bit more hp in the low RPM range as I don't really drive >3000
Would you do it ?
- 3972116 intake (1970 LT-1 replacement part)
- camel hump heads (186)
- Hooker headers into 4" side pipes
- Edelbrock carb
Now I have the opportunity to get a set of :
- Performer RPM intake
- Edelbrock 6089 heads
I'm looking to get a bit more hp in the low RPM range as I don't really drive >3000
Would you do it ?
Had a 1976 L-82, 4-sp
Joined: Mar 2011
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Not if I never rev it up over 3K. Its a waste of money. If you want more low end tq for your driving style, consider an rv cam.
Melting Slicks
Joined: Dec 2009
Posts: 3,229
Likes: 656
From: Thunder Bay
If you can hear the cam at idle, you probably don't need more cam. The Edelbrock RPM intake and heads will certainly be an improvement over what you have. I agree that most of the improvement will be over 3000 rpm, but who doesn't run their Corvette over 3000 rpm? When making power its all about matching parts. It would be very helpful to know what cam you have so you can decide if its an appropriate cam for what you want the engine to do, and what parts are appropriate to go with it.
Burning Brakes
Joined: Mar 2005
Posts: 1,231
Likes: 34
From: Ontario
Probably Best Left Alone
If your engine runs good . has good compression and oil pressure and does not burn oil you would be better off to leave it alone .
Trying to attain specific performance goals doing a partial rebuild is a waste of time and money .
Trying to attain specific performance goals doing a partial rebuild is a waste of time and money .
Le Mans Master
Joined: Apr 2001
Posts: 5,941
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From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
What else do you know about the current setup? What is the compression ratio? Do you know what camshaft is in it now? Has it ever been rebuilt? Parts in the engine really need to compliment each other. Lots of folks mix and match parts without consideration of this. What you end up with then is a none optimized combo that is lacking in performance. I would consider an all around build to meat the goals you want.
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Brett Foote
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thanks guys, good advice, I'm leaning towards keeping it as it is.
I know nothing else about the engine other than what's been posted above.
I've always had a itching for a 5 speed swap, maybe that's the way to go.. have a 3.08 diff with a Muncie..
I know nothing else about the engine other than what's been posted above.
I've always had a itching for a 5 speed swap, maybe that's the way to go.. have a 3.08 diff with a Muncie..
Burning Brakes
Joined: Oct 2012
Posts: 1,152
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The 3.08 is the reason for the lack of grunt. Swap to a 3.36 or steeper. 5-speed along wth the steeper rear gears is very nice combo.
I have a base '69 300hp 350 with 58cc L98 heads for a ~11:1 CR along with a T5 and 3.36 rear. I won't win any drag races but feels great around town!
Last edited by Dynra Rockets; Mar 24, 2018 at 01:11 PM.
Banned Scam/Spammer
Joined: Jul 2015
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Again, if you have 3:08 rear there is absolutely no need for a 5 speed....Unless you were going for a 3:55 or 3:70....
Last edited by zrc3john; Mar 24, 2018 at 01:35 PM.
Melting Slicks
Joined: Dec 2009
Posts: 3,229
Likes: 656
From: Thunder Bay
3.73 gears and a TKO 500 or 600 would wake it up quite a bit, and give you better mileage. But to answer your question, yes I would do the heads and the intake if you're getting a good price on them, but I wouldn't be planning to stop there
Last edited by drwet; Mar 24, 2018 at 02:14 PM.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
wanting more power, hmmm is that a thing? 
sounds like you are making a good decision about
waiting.
make a plan, get a true idea of cost and time.
then the need to upgrade the things more power
has a way of over stressing.
glad it runs good now.
sounds like you are making a good decision about
waiting.
make a plan, get a true idea of cost and time.
then the need to upgrade the things more power
has a way of over stressing.
glad it runs good now.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Install the heads and leave everything else alone......that is what I would do......the LT-1 intake is a surprising piece......it will work well with those heads. If the heads are really 186 casting....then the 64cc Edelbrocks will bump the compression a point.....this will see a benefit everywhere in the curve......hell, the Edelbrocks flow so much better that you would see an increase everywhere anyway.....plus shave 50 lbs. off the front of your car. Pay attention to pushrod length and use only hardened black oxide pieces......go with some Harland Sharp rollers....if you trim the drippers off of the stock valve covers they will fit.
This engine would make an easy 400-410 horsepower and run like gangbusters....
I say do it. But keep the vintage intake for sneaky looks.
Jebby
This engine would make an easy 400-410 horsepower and run like gangbusters....
I say do it. But keep the vintage intake for sneaky looks.
Jebby
Safety Car
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Replace the gears only. 3.73 to 4.10 That is the single most noticeable change that can be made.
Discreet engine mods will essentially have you claim great improvement proportionate to the money you spent. Rear end gears will have you or anyone else that drives the car smiling with OBVIOUS large improvement in pick up and seat of the pants improvement in acceleration.
You know that lull or bog in pickup at 1200 or so rpm, everyone will admit that or lie. The rear gears fix that with your power coming in higher than that and a nice clear feeling (true feeling) of faster acceleration.
Discreet engine mods will essentially have you claim great improvement proportionate to the money you spent. Rear end gears will have you or anyone else that drives the car smiling with OBVIOUS large improvement in pick up and seat of the pants improvement in acceleration.
You know that lull or bog in pickup at 1200 or so rpm, everyone will admit that or lie. The rear gears fix that with your power coming in higher than that and a nice clear feeling (true feeling) of faster acceleration.
Pro
Joined: Oct 2009
Posts: 664
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From: Marysville Ohio
Just a thought- if you are looking for a cheap improvement in the "seat-of-the-pants" feel, what is your timing set at? Engine is not stock so decent chance this is already done, but a performance timing curve may also net some improvement, and it's the cheapest mod that you can feel.
Here is an older post with a lot of good information:
https://www.corvetteforum.com/forums...long-post.html
I would go through this before spending any money on heads/intake/etc. But otherwise, I also agree with Jebbysan if you go ahead with the heads. The timing info is almost universally applicable anyway.
Here is an older post with a lot of good information:
https://www.corvetteforum.com/forums...long-post.html
I would go through this before spending any money on heads/intake/etc. But otherwise, I also agree with Jebbysan if you go ahead with the heads. The timing info is almost universally applicable anyway.
Banned Scam/Spammer
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Replace the gears only. 3.73 to 4.10 That is the single most noticeable change that can be made.
Discreet engine mods will essentially have you claim great improvement proportionate to the money you spent. Rear end gears will have you or anyone else that drives the car smiling with OBVIOUS large improvement in pick up and seat of the pants improvement in acceleration.
You know that lull or bog in pickup at 1200 or so rpm, everyone will admit that or lie. The rear gears fix that with your power coming in higher than that and a nice clear feeling (true feeling) of faster acceleration.
Discreet engine mods will essentially have you claim great improvement proportionate to the money you spent. Rear end gears will have you or anyone else that drives the car smiling with OBVIOUS large improvement in pick up and seat of the pants improvement in acceleration.
You know that lull or bog in pickup at 1200 or so rpm, everyone will admit that or lie. The rear gears fix that with your power coming in higher than that and a nice clear feeling (true feeling) of faster acceleration.