OK, so my engine is done and I'm planning my winter project. Wondering about the merits of having a local speed shop rebuild my 350 (aluminum heads, forged crank, align honed etc.) vs buying a Goodwrench ZZ383.

On the ZZ383 side; the engine is delivered to my door and the money I would spend on having the old engine removed and the new one installed is spent on the engine itself. (for logistical reasons if someone else is building my engine then they are putting it in as well.)

On the rebuild side; the engine would be properly clearanced and balanced.

The cost of both scenarios is pretty well equivalent.
Horse power probably wouldn't be hugely different either in that I'm sure the 425HP GM quotes is over stated.

Your thoughts, experiences and satirical comments are all welcome!
Thanks,
Jon

JSD MOD 27/09/08

 

GM performance crate engines are built in a special facility, not a normal assembly line. They warranty them, knowing they're going to be abused.

Don't worry about whether or not the ZZ383 is properly clearanced.

 

Couldn't have asked for a better response! Thanks as always Five7.
Jon

 

If GM states HP you can bet on it. GM would be my choice.

 

Better still! Thanks,
Jon

 

For sure, if anything, GM will understate the HP a given crate will make. If they have one that consistently makes 500hp on their dyno, they will advertise it as 425hp, simply because not everyone who buys it will know what they are doing when they tune it - so they give the 425hp rating as a "goal" that any idiot can achieve with the given motor, to emiminate any "I want my money back, its not making the power you said it would".

No one complains about their crate engine making too much power, so GM plays it safe and under rates them. They have been doing this for a long time. The 572ci crate is a good example - there are many examples out there of the engine making 70+ hp ABOVE what GM rates the engines at, without changing anything, just correct tuning.

So if you are buying a 425hp engine from a machine shop, you may get 400hp, you may get 450hp - no way to know for sure. If you buy a 425hp engine and know how to tune it properly, you'll get 425hp at the minimum. Probably much higher. Plus a better warranty that will be easier to cash in on, should something go wrong with it.

 

Gotta love TGO!
Jon

 

Pretty sure they dyno those engines with 4 barrel and longtubes.If you do the same you should get the same...roughly.I`d get the 425 zz383.I`ve been eyeballing her for a while.Alredy board with my mild 350.Install it yourself and be done.Or a few more mods and bump up the pwer some more.

 

GM tests their engines with the equipment they recommend you use in the instruction manual that comes with the engines. Like, if they 'recommend' a 750 Holley, thats what they dyno'd and got best results with.

 

To resurect an old thread..

I ordered the ZZ383 and it now reposes in it's crate in a corner of my garage (installation FEB 2009). Never mind that the economy is in the toilet and gas priced are bouncing up and down on a daly basis..whatever.. LOL.

I'm considering ordering a two-piece timing cover to facilitate future cam swaps and am wondering if anyone has anything to say on the matter.

Also, is there any merit to upgrading the timing gear set or better to leave what GM put in? Is there anything else that you think should be done while the engine is on the stand?

Thanks,
Jon

 

I have heard they leak, they are great for dyno mules. I don't think it would save enough time to justify the cost.

 

OK, Thanks.
Jon