Hello. I was going to get them Vortec heads. they flow very well on the intake but on exhaust... its not bad, but definitely could be better. what is does a person do to port the exhaust on these heads to make them flow better? how much can a person take away with the die grinder? Thanks for the help.

 

-=not that I have done it but.....=- you don't wana take much/any material out, they are thin castings. You should polish them and maybe pocket port the material around the valvestem. The exaust side should be mirror polished and the intake side a tad rougher. There was a good website floatig around here about it. Its the same as the "Standard Abrasives" pamphlet. They try to sell grinding accesories.

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-Tas
'89 Formula WS-6
[soon to have Hooker 1-5/8" 50 state legal headers installed]

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

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what tas said.. just remove the casting flaws, narrow the valve guide, and work on the bowl area and smooth the area just above the valve over. You dont want to touch the port floor much at all save for casting flash removal and polishing. Alot of builders like to raise the roof on the exhaust making it into a D shape. I wouldnt mess much with the shape of the port though, whats good for one head may not be good for that head. If you can find pics of pro ported vortec heads, just emulate what you see in the pics

 

What Taz and Pablo said.. and if you do decide to raise the runners,like Pablo said(which actually works well w/ the Vortec head), use whatever header gasket plan to use as a template and do not raise the runner higher than the where the gasket will be, actually I'd stay a little lower to compensate for alignment problems if this is the first time you've done this. Having a huge exhaust port that runs directly into a small header/header gasket is like pissing in a fan!! Just remember that the Vortec head makes a lot of torque due to its conservative exhaust flow #'s and going bigger on the exhaust will decrease some of the low end which would require high convertor+gears+RPM to perform at its potential. Just do a little bowl blending, narrow the valve guide boss, clean up rough edges, and if you do raise the runners, do it consevatively, and polish them will a 80 - 120 flapper wheel and you'll be OK. Also like Pablo said, take VERY little off the floor, just clean the up a little.

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82 Z28 350, Ported #882 Heads, Performer RPM cam and intake, hedman headers,650 Demon carb,
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