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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Silverado1979 on April 24, 2013, 11:13:56 am
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I've got a 79 that is totally original. Everything on the engine is stock. I am looking for upgrades that will increase low-rpm h.p. The engine is in really good shape with only 52000 miles. I would like a little better throttle response, pick up, and mpg.
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you mean.. low rpm torque, thats what you want... anyways.. is it carb or tbi? and are you subject to emission inspections? either carb or injected, you can start by adding some headers... btw how much are you willing to spend?
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It has the stock 4 barrel carb. No emissions inspection needed. Don't want to spend a ton, but willing to put decent money into it.
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by a 4 barrel carb.. i´m guessing its a quadrajet.. thats a good carb... with a light foot its like if you only had a 2 barrel enough for easy driving.. you step on the gas pedal and now all of a sudden you have a bigger carb.. anyways.. give your engine a tune up... change the plugs, filters, cap and coil on the distributor... maybe a set of wires.. once thats done.. might consider the headers and an intake... lets see what others might come up with... by the way.. adjust your timing to make it more efficient too...
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X2 what Gildardo01 said...
Going beyond what a well tuned factory 1979 engine will provide will really depend upon how much you want to spend.
The heads you have are probably not the greatest flowing heads, a port and polish could help or just swap them for pretty much any of the newer heads. If the pistons are stock dished (most likely), you won't build a lot of compression. A head with a smaller combustion chamber (e.g., 64 cc) and a thinner head gasket can help to build compression. For the money, the GM Vortec heads are a pretty good value; but you will need to use an Vortec specific intake manifold for those heads.
Headers will help a lot for both torque and horsepower, but you get what you pay for. A good set of headers will be pricey.
Once you have an idea of what direction you want to go with heads, headers, etc.; call up your favorite cam company and tell them what you have and what performance you desire and they will provide what you need...
I'm sure more insight will be provided by others.
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yeah vortec heads are cheap and really good.. you can by new ones for about 600 or so a set and if you were thinking about buying an intake already might as well buy the one for the vortec heads... this set will give you atleast 50+hp... then again if its out of your budget.. just buy a used intake from eBay... i got one from ebay once for about 40 bucks.. an edelbrock performer.. and the headers ive used headman headers before and their cheap and pretty good headers... about 160 a pair...
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What gear ratio do you have? Sounds like you need to start there to me and where you'll get what you're looking for.
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What gear ratio do you have? Sounds like you need to start there to me and where you'll get what you're looking for.
just curious... why gear ratio... if a shorter gear is installed mpg are affected but it will be more responsive because the engine is running at a higher RPM... if a taller gear is installed mpg are benefited but its not going to be a quick starting from a stand still... actually in normal city driving one can barely tell... but on the highway you will really notice in the rpms..
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What gear ratio do you have? Sounds like you need to start there to me and where you'll get what you're looking for.
2.52, 1.52, 1.00:1
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+2/3/4
Tune up first and fore most.. plugs, wires, distributor (timing set will do wonders), distributor cap and rotor button, change all the fluids. Then heads, headers, exhaust...keeping it single with say 3" and maybe 2.5 split out the back will help keep that low end torque to move that air plow of yours...then its on to intake manifold, camshaft and if you really want it just for the ease of tuning and ability to rebuild get a newer carb. But honestly don't trash that Quadrajet there are a lot of people who will pay good money for a decent one because they know how to use them right. Oh and while you are at it change your filters and don't neglect the fuel filters you should have 2 someone will correct me if I am wrong.
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Can a quadrajet fit on top of a vortec intake manifold? I'm thinking I should eventually go the vortec route, but will start with a good tune up and a better exhaust.
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Yes, a quadrajet will fit, just get the spread bore style intake. I am building a Vortec motor and plan on using my original quadrajet.
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I found a few people selling vortec heads on Craigslist. I was wondering if it would be worth it to buy them used. I found some straight off a 97 for $150. I also found some that were cleaned and had the valves ground and the springs tested for $275. What route should I take? I've also never done engine work. Are changing heads difficult or is it just a couple bolts?
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Are you going to be doing any towing or hauling?
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Try to find some heads local, so you can look at them before buying. If they will let you take them to a machinist for inspection and get your money back if there is a problem....even better.
Its not difficult removing the old heads and installing the new ones. There are rebuilding books available and take pictures as you go to refer to, upon re-assembly.
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What's the final drive ratio in the rear end?