I don't know if that makes my car go faster, but it keeps a smile on my face...
Performance suggestions for a 73
Thread Starter
Cruising
Joined: Jul 2005
Posts: 10
Likes: 0
Performance suggestions for a 73
I have a bone stock 73 coupe with 350/4bbl. I wanted to see if i could get a little more performance out of her. I only drive it on the weekends, but wanted to get advice on some low cost & not to radical ideas. i've been looking at getting a holley carb and petronix ignition setup.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Those two may not add any performance, but reliability may improve a bit. It's hard to get any real power increases without going inside the engine. Maybe you can up-grade the exhaust with headers and a free-flowing exhaust, and a performance intake manifold...G/L
Melting Slicks
Joined: May 2005
Posts: 2,143
Likes: 0
From: San Diego California
Originally Posted by big_G
Those two may not add any performance, but reliability may improve a bit. It's hard to get any real power increases without going inside the engine. Maybe you can up-grade the exhaust with headers and a free-flowing exhaust, and a performance intake manifold...G/L
work on that exhaust 
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
The cheapest way to do this is:
1) Headers and a good low restriction exhaust system.
2) A street port and three angle valve Job on the cylinder heads.
3) A mild performance camshaft.
The stock intake manifold and carburetor can keep up with these modifications. The next step after this is a mild performance intake manifold. If you need more after the intake it will cost you.
Modifying the '70's engines is all about removing bottlenecks. The worst one is the stock exhaust. After that is the cylinder heads. To keep it cheap you tune up what you have. A street port job (you can do that yourself) and a three angle valve job isn't all that expensive. The nice thing about this system of modification is that you can stop at any time and each modification supports the one after it. Headers will allow the cylinder heads to work better. The head work you did will take full advantage of that new camshaft.
These three modification together can yield 60 to 80 horsepower. If you want to add an intake manifold it will be icing on the cake.
After this the bottleneck again becomes the cylinder heads. If you want more you'll need new heads. If you're going to spend the money you may as well get aluminum ones to take some weight off the front of the car. Modern heads will raise the compression ratio a little.
If you have become a horsepower junkie the only choices you have after new heads is higher compression or forced induction, unless you want to spray it. Either way it means it's rebuild time. Money, money, money!!
BigBlockk
Later.....
1) Headers and a good low restriction exhaust system.
2) A street port and three angle valve Job on the cylinder heads.
3) A mild performance camshaft.
The stock intake manifold and carburetor can keep up with these modifications. The next step after this is a mild performance intake manifold. If you need more after the intake it will cost you.
Modifying the '70's engines is all about removing bottlenecks. The worst one is the stock exhaust. After that is the cylinder heads. To keep it cheap you tune up what you have. A street port job (you can do that yourself) and a three angle valve job isn't all that expensive. The nice thing about this system of modification is that you can stop at any time and each modification supports the one after it. Headers will allow the cylinder heads to work better. The head work you did will take full advantage of that new camshaft.
These three modification together can yield 60 to 80 horsepower. If you want to add an intake manifold it will be icing on the cake.
After this the bottleneck again becomes the cylinder heads. If you want more you'll need new heads. If you're going to spend the money you may as well get aluminum ones to take some weight off the front of the car. Modern heads will raise the compression ratio a little.
If you have become a horsepower junkie the only choices you have after new heads is higher compression or forced induction, unless you want to spray it. Either way it means it's rebuild time. Money, money, money!!
BigBlockk
Later.....
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Melting Slicks
Joined: Jan 2004
Posts: 2,527
Likes: 1
From: St. Petersburg, Fl///Columbus, Ohio
My '73 got a new powerplant
Hopped up (by me) 350R vortec engine, HEI, Hooker headers/sidepipes, Eldelbrock carb, GM performance Intake, Hot cam, 1.6 RR's, Zoom clutch and an engine stand.... so my numbers matching engine is safe and sound in the garage!!!
I think the Value of the 73's are going to go up pretty quick. If you have the origional engine... leave it alone!!! buy an engine to blow-up without decreasing resale on your car!!
Hopped up (by me) 350R vortec engine, HEI, Hooker headers/sidepipes, Eldelbrock carb, GM performance Intake, Hot cam, 1.6 RR's, Zoom clutch and an engine stand.... so my numbers matching engine is safe and sound in the garage!!!
I think the Value of the 73's are going to go up pretty quick. If you have the origional engine... leave it alone!!! buy an engine to blow-up without decreasing resale on your car!!
