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I have taken my 882 casting heads to the machine shop to get ARP screw in studs, valve job, and springs. I was wondering how much more power will I get by swapping the valves from 1.94 and 1.50 to 2.02 and 1.60, the guy kind of talked me into it. And how much power should these heads be able to support/produce? With some minor port and polishing.
 

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Of course he talked you into it, he's making money doing that. After you spend a BUNCH of money on machine work with new SS valves you'll still have a slug of a head that will cost more to rebuild and still won't hold a candle to new out of the box Vortec heads.

The 882's won't flow enough to reach the rpm necessary to see any differnce in perf between 1.94 or 2.02. I wouldn't waste my time or money on the 882's.
 

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lizardking7750 said:
I was wondering how much more power will I get by swapping the valves from 1.94 and 1.50 to 2.02 and 1.60, the guy kind of talked me into it. And how much power should these heads be able to support/produce?
Below 3500 RPM, they'll make LESS power, not until 4000 or so will you break even. And this is providing they've been properly ported to transition the larger seats into the bowl where the 1.94 x 1.50 valves used to be.
 

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lizardking7750 said:
Thats ugh...... not good.
Are these 64cc chamber heads? If so, changing to 2.02 will actually decrease power unless you deshroud the chamber around the valve nearest the wall.. When you enlarge a valve it will then be closer to the chamber wall, which means it now has less room for airflow around the valve on that side so it needs to be deshrouded to gain back the benifits of the larger valve, otherwise there will be a performance loss.. But by doing so you will also loose some compression (catch 22). Many years ago I soaked a ton of money into a old set of castings and will never go that route again unless I'm trying to meet some type of stock class or something.. After all that work and money I decided to try a pair of out-of-the-box Dart Iron Eagles with no mods and I knocked .4 seconds off my time slip (live and learn)..
 

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If you're willing to drop all taht money on POS heads do yourself a favor and buy some complete entry aftermarket heads. And yea, not paying for those would be an as5hole thing to do, BUT any machinist who doesn't take the time to instruct you that those are POS heads deserves what he gets. He should have spoke up about it rather than just trying to sell more crap.
 

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lizardking7750 said:
I already paid a little bit of money for a down payment so.......
What a man would do- and it sounds like you want to be a man about this- and good for you on that- it's just too easy to take the punk's way out these days and say "It's not MY fault!" but that's BS and you and I both know it, right?

Call the machinist ASAP- tell him to stop work, better yet go there in person, if he's unscrupulous he'll throw them on and be working them before you get there and then you're out at least the deposit.

Anyway, if he hasn't started work on them yet, get your deposit back less a generous 15% for his time and trouble (this shouldn't be necessary, but shows you're not out to screw anybody). If he's a decent guy, he'll refund you all your money if no work was done.

If he's started work, then your options are limited to paying for what he's done, abandoning them or seeing the whole thing through and paying for a pos head to be modified.
 
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