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port and polish

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hey. i want to port and polish the heads on my 5.7. does anyone have experience with it? What kind of time frame am i looking at being that it is my first time? What tools do I need (i think a dremel, misc dremel attachments. not sure what else)? What kind of power gains can I expect (torque and hp)? I have heard that it is not that difficult and the only thing that really makes me nervous is port matching...any advice is appreciated!! Thanks!!

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Dont even mess with porting the heads especially if you havent done it before, send them in or leave it alone. You can really screw up the motor if you port them way to much. Im thinking you want to do this on your truck, if its your daily driver leave it alone and throw and exhaust on it.

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You can smooth out the bumps and ridges from casting, as well as the bump where the valve seats are pressed in with a dremel tool. For gasket matching you just center the gasket over the ports and trace the opening with a sharpie. To do a good job it might take around 30min per port x16 and longer if you decide to gasket match the intake manifold. Dont get carried away and hog out the head. You can hurt performance very easily.

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Dont even mess with porting the heads especially if you havent done it before, send them in or leave it alone. You can really screw up the motor if you port them way to much. Im thinking you want to do this on your truck, if its your daily driver leave it alone and throw and exhaust on it.

+1 You may end up with a set of heads that perform worse than it does now.

Steve

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Dont even mess with porting the heads especially if you havent done it before, send them in or leave it alone. You can really screw up the motor if you port them way to much. Im thinking you want to do this on your truck, if its your daily driver leave it alone and throw and exhaust on it.

thanks for the input although this truck is way past throwing an exhaust on...its already got doug thorley headers, high flow cats, and a magnaflow muffler, its reprogrammed, throttle body spacers, k&n intake, dif. coil, etc etc...i was thinking about JUST polishing them after doing more research, although it doesn't seem too difficult. will polishing only with no porting make a noticeable difference? any idea wut kinda power differences could b expected?

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You can smooth out the bumps and ridges from casting, as well as the bump where the valve seats are pressed in with a dremel tool. For gasket matching you just center the gasket over the ports and trace the opening with a sharpie. To do a good job it might take around 30min per port x16 and longer if you decide to gasket match the intake manifold. Dont get carried away and hog out the head. You can hurt performance very easily.

that makes alot of sense with the port matching...i did alot of google searches and couldn't really find a difinitive answer as to how to do it. i'm still debating lol. thanks!

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You can get in there with a dremel and smooth out any casting flaws that might obstruct airflow. You can polish the exhaust ports to prevent carbon buildup, but I would leave the intake ports with a rough finish. When you do the gasket matching make sure you keep the ports nice and straight so you dont get a V shape where the ports come together. Its hard to say if you will get a noticeable difference on the ass dyno with just cleaning up the ports. For a free upgrade it might do good. Have you ever thought of upgrading the cam?

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Just match the gaskets.......

any more is really a waste of your time.

All the current heads are casted to way better tolerances then they were in the 60's - 80's.

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You can get in there with a dremel and smooth out any casting flaws that might obstruct airflow. You can polish the exhaust ports to prevent carbon buildup, but I would leave the intake ports with a rough finish. When you do the gasket matching make sure you keep the ports nice and straight so you dont get a V shape where the ports come together. Its hard to say if you will get a noticeable difference on the ass dyno with just cleaning up the ports. For a free upgrade it might do good. Have you ever thought of upgrading the cam?

ya i think i am going to get a long block from hiperformer.com. they give a 7 year 100k mile warranty on all their blocks and i was going to have them put an rv cam in it so i'd have a little more torque and the stock ecu will accept it.

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find some junkyard heads to practice on!!!!!!!!!!!!!!!!!!!!!!!!

my neighbor has tons sittin in his yard so i might ask if i can take one off his hands and clean it up to practice on lol

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What year is the truck? I dont think there is much potential in the TBI heads. A good upgrade would be a set of Vortec heads from a 96-2000 5.7l truck. 1/2 and light duty 3/4 ton,gvw under 7200lbs. There was a differance in the HD 3/4 and 1 ton heads that caused a slight power drop. You would need a Vortec specific intake manifold also. Edelbrok and GMPP have them. No programming needed from what I understand.

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by the time your done wearing your fingers out with those irons, get a set of factory vortechs (like posted above) those are shabby ports and you dont have enough meat in em to make em perform

you can get away with the factory intake by enlarging the center holes and grinding the edge so the bolts sit flush

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What year is the truck? I dont think there is much potential in the TBI heads. A good upgrade would be a set of Vortec heads from a 96-2000 5.7l truck. 1/2 and light duty 3/4 ton,gvw under 7200lbs. There was a differance in the HD 3/4 and 1 ton heads that caused a slight power drop. You would need a Vortec specific intake manifold also. Edelbrok and GMPP have them. No programming needed from what I understand.

the truck is a 95. will the stock ecu work with those heads? how much do they go for?

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Stock ecu will work, Ive seen them at Scoggin Dickey Chevrolet, look them up on the web, for around 6-700 bucks. Great bang for the buck set of heads. Scoggin Dickey sells a complete conversion kit for TBI powered trucks. I believe it comes with everything you will need. I have a set that will be going on my 91 RCSB 2wd Sierra. I have the Edelbrok MPFI set up and will be using the GM Performance Parts Hot Cam kit in a ZZ3 crate motor short block. How big of a cam are you going to use? The Vortecs require some machine work with anything over .480 lift. The GM Hot Cam is .525 with 1.6 roller rockers so mine will need some machining.

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Stock ecu will work, Ive seen them at Scoggin Dickey Chevrolet, look them up on the web, for around 6-700 bucks. Great bang for the buck set of heads. Scoggin Dickey sells a complete conversion kit for TBI powered trucks. I believe it comes with everything you will need. I have a set that will be going on my 91 RCSB 2wd Sierra. I have the Edelbrok MPFI set up and will be using the GM Performance Parts Hot Cam kit in a ZZ3 crate motor short block. How big of a cam are you going to use? The Vortecs require some machine work with anything over .480 lift. The GM Hot Cam is .525 with 1.6 roller rockers so mine will need some machining.

i am thinking most likely of going with an rv cam which i think is somewhere around .480 but i'm not positive. when you do your motor, will it all be 50 state legal? that's the bind i'm in...

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It should pass our emissions test. The fuel injection is 50 state legal. My headers are 50 state also. So visualy it should pass also. The cam might be a problem but I heard that with some tuning it would pass.

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You can't beat the vortecs for bang for the buck. You could spend a LOT of time on your heads and not get as much power with just bolting on some vortecs. I don't know when they came out though, so check your truck to make sure you don't already have them.

If you decide you're going to port anyway, get some junkers from your neighbor and practice first. Take your time, just remove a bit at a time.

And wear a full face shield! Even if you have safety glasses on you can still get metal in your eye and need to go to the hospital. Don't ask how I know.

Use carbide bits and an air tool if you can. A dremel might suck on cast iron heads.

Here's my first porting job. The guy who was mentoring me through this figured this was worth about 15-30 HP. No way to tell how much for real without back to back dyno runs. I only removed the ridge that you can see in the pics, nothing more. More important for the exhaust than the intake 👍

2464576529_95fe14231e.jpg?v=0

After:

2465408076_0528878157.jpg?v=0

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No,man I say just go for it,but listen to what other TTers are saying,dont go in and hogg the crap out of them,do a very good clean up of the ports,and smooth out the casting ridges,leave the intakes with a rough finish,and polish the exhaust ports to a mirror finish,remember,dont over do it,Im doing the same thing to a 300-6 head,as i write this,first i had it hot tanked,decked,sonic checked for cracks and maga-fluxed,and what ever else they do to one before a re-build,it came out to 80 bucks for the machine work,[i done some aluminum welding for the owner,and i know him]they still got my valves and springs and the rest of that jazz to finish the 3 angle valve job when im done porting the head.Im either gonna paint the re-built motor Ford grey,or blue,what say you:confused: 👍

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Vortecs were first introduced in 96 when GM went to central port fuel injection. His truck doesnt have them.

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