Carb, intake and exhaust advice
#1
11-20-2022, 09:33 AM
Carb, intake and exhaust advice
Hi
I recently acquired a 68 base model . It is a completely stock 327. I am looking to add a new intake, 4 barrel carb. These are probably the only changes I will be making , just want to use the car for nice drives, and looking for a little more power . Asking for any advice on a good carb and intake . I have a cast 4 barrel intake from another small block too, or is there a better aluminum intake to use ?
Thanks !
I recently acquired a 68 base model . It is a completely stock 327. I am looking to add a new intake, 4 barrel carb. These are probably the only changes I will be making , just want to use the car for nice drives, and looking for a little more power . Asking for any advice on a good carb and intake . I have a cast 4 barrel intake from another small block too, or is there a better aluminum intake to use ?
Thanks !
#2
11-20-2022, 10:59 AM
Headers are really a must IMO if you want to do this upgrade,the motor needs to breathe out as well as it does in.
There's lots of kits out there for intake and carb,just don't go too big,without a cam and head upgrade you'd just be wasting gas.
Here's a nice reasonably priced kit that comes with hardware and gaskets.
https://www.ebay.com/itm/19524562721...IaAiIREALw_wcB
There's lots of kits out there for intake and carb,just don't go too big,without a cam and head upgrade you'd just be wasting gas.
Here's a nice reasonably priced kit that comes with hardware and gaskets.
https://www.ebay.com/itm/19524562721...IaAiIREALw_wcB
#4
11-20-2022, 12:50 PM
Well you can get headers for a lot less but you'll get what you paid for.
I bought ARH stainless for my car and they're a great product.
Cheap headers can have fitment issues and typically will rust after a while,I've had the ARH on my car 6 years and they still look like new.
They also make a complete exhaust system for your car,again expensive but top notch and will last forever.
On a stock 327 the 1 5/8" would be fine,if you want to build it or a bigger motor in the future you might go the next size up.
https://americanracingheaders.com/co...7-1969-headers
https://americanracingheaders.com/co...r-back-exhaust
I bought ARH stainless for my car and they're a great product.
Cheap headers can have fitment issues and typically will rust after a while,I've had the ARH on my car 6 years and they still look like new.
They also make a complete exhaust system for your car,again expensive but top notch and will last forever.
On a stock 327 the 1 5/8" would be fine,if you want to build it or a bigger motor in the future you might go the next size up.
https://americanracingheaders.com/co...7-1969-headers
https://americanracingheaders.com/co...r-back-exhaust
#5
11-21-2022, 07:03 AM
This may get a little wordy.
When modifying and engine to increase performance the first question you need to ask yourself is what do I want? Are you looking to get the max hp numbers out of what you have? Are you looking for a better driving experience in normal roadway driving or do you want to race. Even though we are only talking about bolt on part there would be a difference in the parts you would want and mis matching parts can mean the car is really good at nothing.
Max HP on a dyno = Long tube header and a single plane manifold maybe a 675 CFM carb.
This is what I hear the most guys want. Keep in mind these upgrades show up in the 5000+ rpm range and may have less HP at 2500-4500 RPMs.
Mid range power = Mid length headers and dual plane intake and a 625 CFM carb
This is what I call a driver. If you are driving down the highway normally and you punch it at 3000 RPMs you will feel the new power. But your max dyno output WILL be less. Assuming you have stock gears this type of setup will be faster than the above setup until about 80 MPH.
Low range power is more of a truck thing so I will not even review that.
Without changing the cam neither setups will change things dramatically. If you decide to change the cam in the future call the CAM manufacture and let them know what you have and what you want out of the car and they will recommend the correct cam. Again following a path with match parts is always the best idea. I have seen too many guys buy aftermarket stuff that is not matched well. Mid length headers and a single plane carb with a stage one tow cam. No one is happy with that setup. If you already have these matched upgrades and you add the right cam then the motor difference will be night and day.
As stated above regardless of what design you want do not skimp on the parts. First gen Camaros tend to be owned for a long time if you buy cheap headers you will end up regretting it. I have seen guy switch back to stock manifold after constant issues with a cheap set of headers after just a few years. The headers on my 67 are not the best but they are Blackjack aluminum coated from the mid 90s and have never given me an issue. I plan on switch to a good stainless steel set when I do my next exhaust upgrade.
My hope is you would just see this post as an opening of a door, Now do your own research. There is tons of info out there. The downside is there is a lot of info from people who do not understand and are going by what they did once or info they read somewhere. The more you read the more you understand. The 327 is an interesting platform because it has served Chevy in so many ways. It has been the economic engine, the mid range upgrade and the over 300 hp corvette top dog. Manufacturers specs and info will always be on the positive side for their products but if it is a US name brand you can assume any spec they list is that can be verified is going to be right. One benefit to all these youtubers they keep manufactures honest. It is amazing to see so many guys willing to share information and they have dynos.
When modifying and engine to increase performance the first question you need to ask yourself is what do I want? Are you looking to get the max hp numbers out of what you have? Are you looking for a better driving experience in normal roadway driving or do you want to race. Even though we are only talking about bolt on part there would be a difference in the parts you would want and mis matching parts can mean the car is really good at nothing.
Max HP on a dyno = Long tube header and a single plane manifold maybe a 675 CFM carb.
This is what I hear the most guys want. Keep in mind these upgrades show up in the 5000+ rpm range and may have less HP at 2500-4500 RPMs.
Mid range power = Mid length headers and dual plane intake and a 625 CFM carb
This is what I call a driver. If you are driving down the highway normally and you punch it at 3000 RPMs you will feel the new power. But your max dyno output WILL be less. Assuming you have stock gears this type of setup will be faster than the above setup until about 80 MPH.
Low range power is more of a truck thing so I will not even review that.
Without changing the cam neither setups will change things dramatically. If you decide to change the cam in the future call the CAM manufacture and let them know what you have and what you want out of the car and they will recommend the correct cam. Again following a path with match parts is always the best idea. I have seen too many guys buy aftermarket stuff that is not matched well. Mid length headers and a single plane carb with a stage one tow cam. No one is happy with that setup. If you already have these matched upgrades and you add the right cam then the motor difference will be night and day.
As stated above regardless of what design you want do not skimp on the parts. First gen Camaros tend to be owned for a long time if you buy cheap headers you will end up regretting it. I have seen guy switch back to stock manifold after constant issues with a cheap set of headers after just a few years. The headers on my 67 are not the best but they are Blackjack aluminum coated from the mid 90s and have never given me an issue. I plan on switch to a good stainless steel set when I do my next exhaust upgrade.
My hope is you would just see this post as an opening of a door, Now do your own research. There is tons of info out there. The downside is there is a lot of info from people who do not understand and are going by what they did once or info they read somewhere. The more you read the more you understand. The 327 is an interesting platform because it has served Chevy in so many ways. It has been the economic engine, the mid range upgrade and the over 300 hp corvette top dog. Manufacturers specs and info will always be on the positive side for their products but if it is a US name brand you can assume any spec they list is that can be verified is going to be right. One benefit to all these youtubers they keep manufactures honest. It is amazing to see so many guys willing to share information and they have dynos.
Last edited by Gorn; 11-21-2022 at 07:21 AM.
#6
11-24-2022, 09:13 AM
OP
I also had base model 2 brl 327. I put on a Edelbrock Performer intake and their 1406 (600cfm) 4 brl carb. Was solid right out of the box with just a minor fuel mixture adjustment. Also had a 2 1/4" true dual exhaust put on. that REALLY woke up the car
If you still have a points dizzy, swap over to a Pertronix unit for it
Rear gear ratio is also a way of getting way more acceleration but will sacrifice Fwy speed cruising RPM. 3:73 are fun on the street but suck on Fwy over 65 mph unless you put in an OD trans
I also had base model 2 brl 327. I put on a Edelbrock Performer intake and their 1406 (600cfm) 4 brl carb. Was solid right out of the box with just a minor fuel mixture adjustment. Also had a 2 1/4" true dual exhaust put on. that REALLY woke up the car
If you still have a points dizzy, swap over to a Pertronix unit for it
Rear gear ratio is also a way of getting way more acceleration but will sacrifice Fwy speed cruising RPM. 3:73 are fun on the street but suck on Fwy over 65 mph unless you put in an OD trans
#7
11-24-2022, 11:53 AM
Or slip in an HEI unit from a later model,my '78 pickup is reliable as a Timex watch in no small part because of the HEI Dist.
#8
11-24-2022, 02:17 PM
The later model HEI are quite large and dizzy to firewall space is quite tight on 1st gens. Yeah I know guys running HEI dizzy with coil in cap
For me I just swap in a Pertronix unit in stock dizzy. my 67 Camaro and 72 C10 both have them
If I had to buy a HEI dizzy I would also just get the Pertronix Dizzy as its a small cap one just like a points dizzy set up to use an external coil
whatever one wants, IMHO a HEI is better than points but some swear by them. each to their own
For me I just swap in a Pertronix unit in stock dizzy. my 67 Camaro and 72 C10 both have them
If I had to buy a HEI dizzy I would also just get the Pertronix Dizzy as its a small cap one just like a points dizzy set up to use an external coil
whatever one wants, IMHO a HEI is better than points but some swear by them. each to their own
#10
11-26-2022, 07:56 PM
The main downside with the pertronix kits is if you are traveling and it fails on a weekend you will have to cross your fingers someone near you will have one. The downside with HEI It has been my experience that they fit some first gens and require a few wacks with a hammer to the fire wall on others. It is not based on the year, so I guess its manufacture variation? Also I am told the HEI spark modules are less dependable now than they were 30 years ago. Most guys I know that run them do keep a spare in the glove box.
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