« Reply #15 on: January 03, 2007, 11:31:00 am »
They did. Even put 800's on the 302 in the 1st-gen Z/28s. Doesn't mean they were kinda overcarbed though. Not sure why GM did that on quite a few of their motors but they did. I would think driveability would suffer from it. But that's the beauty of a spead-bore: small primaries for good throttle response around town and part throttle, and big secondaries to draw a lot of air in at WOT. Problem is that stumble when you stomp on it and the big secondaries open and the motor can't use all that available air, plus the resultant slow down in airflow velocity when the big ports open up that the motor can't use yet since it's still at low revs.

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85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.