73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: ajm1109 on April 26, 2014, 11:23:32 am
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Ok to start I bought this truck about 2 months. I have done some research already and this is what i know i got: GM 92 Crate 350 4 bolt main, Edelbrock Victor Jr intake, Comp Cams Thumper cam, Edelbrock 1411 750 cfm electric choke, and Headman performer headers with flowmaster exhaust. Im not sure on what heads i have and the rear end has a GM 86 stamp on the driverside front. It is a 12 bolt rear end but im not sure of the gear ratio. The truck also has 22in tires on it as well. Im currently looking for a different set of rims and tires. lol
It sounds great i do love the choppy idle but i am more of a performance guy. I would rather be fast than sound fast, you know what i mean.
So my question is what can i do with what i have or what should i change to have more low end torque and power. Everything I've read tells me that this set up is wrong. I have a high rpm intake and a virtually no low end cam. And im not sure if a 750 is to much carb or not.
Any suggestions will be helpful as I am new to the Chevy world.
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My $0.02, I think you've identified some of the culprits for the lack of low-end torque...
Other things to look into are: what gear ratio in your rear axle? Transmission? Convertor stall rpm (if automatic transmission)?
You should try to figure out what heads you have before trying to replace engine parts (i.e., intake manifold). A dual plane intake and a smaller cam would help low end torque.
Your cylinder heads can also be a big factor in low end torque, so again you should try to figure out what you have.
The 750 cfm carburetor is more than a 350 really needs but probably not your biggest issue right now...
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Jason S
well i have the TH400 Automatic tranny and im not sure on the rear gear ratio. I was told that they were 305 heads on the motor but im not sure if the source was really reliable.
Im just more looking for info on a better setup utilizing as much as i can for my original setup.
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You're on the right track here but pull a valve cover and post the casting # here. There are many of us and many a google search that can tell you what you're working with just based on that. The victor Jr is a fine piece, but its a high rpm one by design. A good dual plane like an edelbrock performer air gap will go a long ways for you. As suggested before, rear end ratio will play a huge role here also. And my personal experience with 305 heads is not good. Small chambers sure, but small runners and even smaller valves kill whatever the bump in compression gave it. You'll get much more info on that when posting a casting number though.