Thread: Problem with new ZZ4 350 Motor

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Here's another few threads that may be of value. It gives a GM vacuum canister part number better suited for the ZZ4.

http://www.sallee-chevrolet.com/Disc.../653/2608.html

http://www.sallee-chevrolet.com/Disc.../653/2297.html

The tech guy at Sallee Chevrolet recommends NO VACUUM ADVANCE - just disconnect. Or, if you want vacuum advance for a little more mileage, get part #1973681 and replace the stock vacuum canister. This cannister puts in 10 deg of vacuum instead of 20. and has a stiffer spring. If this one is used, ported (timed) vacuum is recommended. The part is available from http://www.gmpartsdirect.com for $22.81, including shipping. I'm going to give it a try.

This question set me off on a research binge, because I have a Fast Burn 385 with basically the same specs - just a little more HP.