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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: bigjoe62b on August 11, 2014, 02:57:21 pm

Title: Engine for drag racing
Post by: bigjoe62b on August 11, 2014, 02:57:21 pm
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Hi Guys. I have a 86 Chevy Stepside with a 454 and th350 box. I don't know the exact rear end gears on the truck but I counted the rotations and assume they are 3.73 or 3.90's. I haven't pulled the diff cover off to count the teeth. My question is I want the truck to run somewhere in the 12's on the strip and am unsure of the best way to go with the engine. I have a large cam and single plane dart manifold for rectangle port heads but not sure if the power band would be too high for the stock heads or the stock torque converter. Would it be best to keep the dual plane manifold and put in a low power band camshaft and keep the oval port heads. I have a few big blocks so can set them up different but would have to be on a limited budget. Any advice you guys could give would be great. Thanks
Title: Re: Engine for drag racing
Post by: bigjoe62b on August 11, 2014, 03:20:26 pm
Forgot to mention that I am going to bump the compression up in the motor with hopefully forged pistons to somewhere in the 9 to 1 range.
Title: Re: Engine for drag racing
Post by: Engineer on August 11, 2014, 03:40:30 pm
How many RPMs do you plan on turning? Stock stall speed converter? If not over 6,000 on the max RPMs I would stay with the oval port heads, Holley Strip Dominator intake, and a strong low end hydraulic roller cam. Add a 4160 Holley 750 vac secondary carb to it for good off the line response.

If you aren't going to a larger stall converter then you will need to build for low end grunt.
Title: Re: Engine for drag racing
Post by: bigjoe62b on August 11, 2014, 04:01:40 pm
Wasn't really going to turn it over 6000. As far as I'm aware it is the factory stall converter. I have both rectangle heads and oval port sitting around so neither is a problem to install. I also have a Holley 750 laying about so no problem there. The engine in the truck at the moment has oval ports and an edelbrock performer 2-0 on it and an edelbrock 1406 carb.
Title: Re: Engine for drag racing
Post by: bigjoe62b on August 11, 2014, 04:04:52 pm
What I was really hoping for was 500hp at the flywheel.
Title: Re: Engine for drag racing
Post by: NCali on August 16, 2014, 10:10:26 pm
how do you plan on keeping those 500 hp from twisting the frame into a pretzel. If the twist  of a steering box will crack the frame, 500 hp really ought to do the trick
Title: Re: Engine for drag racing
Post by: Captkaos on August 17, 2014, 11:47:51 am
Mine survied fine with 500hp.  When you start hook it is up you will start finding all the weak points in the drivetrain...
Title: Re: Engine for drag racing
Post by: bigjoe62b on August 20, 2014, 09:09:16 am
I think the frame will take it. The drivetrain might struggle.
Break, Fix, Race, Repeat


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Title: Re: Engine for drag racing
Post by: fitz on August 20, 2014, 05:46:10 pm
Have you run the truck at the track to get a 1/4 mile time for the current set up?
Like Captkaos mentioned, traction will find your weak link. Still running a stock 10 bolt?
Title: Re: Engine for drag racing
Post by: bigjoe62b on August 22, 2014, 04:03:44 pm
Yeah. 10 bolt. Think it's had a few modifications anyway. It used to belong to the San Diego fishing company and it had some changes. 700r4 changed to th350. Trans cooler installed. Different rearend gears and I think it's got an limited slip in it. Think it must have been used to tow boats. Not had it at the track yet. Not a great deal of public track days here here in the UK. This was more for the future though. So miss Texas and every Friday night was track time


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