Thread: 350 HO Vortec

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I recently purchased a 76 Jeep CJ7 installed with a newer Chevy 350 HO 330 HP crate motor (2,000 miles) with an Edelbrock intake manifold and 1406 carb (600?) It has an HEI Summit Racing distributor.

I drove the vehicle home from Portland to SLC this past week. Two questions;

- The vehicle was running quite rough on the way home, appearing to not be running on all cylinders, poor carburation, or lack of proper timing as I was unable to determine the obvious until I arrived home. The plug wires were placed in the wrong position by the previous owner (6 & 8 were reversed.) Have I potentially caused serious damage to the engine by running 800+ miles with this setup?

- What should be the proper timing for this engine with the current setup?

Thanks in advance!.
Bob.

If it runs OK with the wires properly set up, probably no damage. Did it overheat?

With the vacuum advance plugged, set it at 10 degrees btdc at about 700 RPM.

As a check, if you have a timing tape or a degreed balancer, run up the RPMs until the timing stops advancing. It should be about 32 degrees.

Jack,

The engine held its tempurature during the trip. It appears to be running great, now.

I remember the previous owner mentioning something about a Cromally cam that is installed which pushes the timing to 11-12 degrees BTDC?

Thanks again.
Bob.

Bob,

The spec sheet recommends no more than 32 degrees. Not that that's set in stone. He may have installed a cam that allows a little more lead. You can fiddle with the timing a few degrees each way and see what happens. Keep away from any ping. These Vortec engines don't need a lot of timing lead.

I don't worry about initial timing any more. I spin the motor up until the timing stops advancing, then lock it in at the recommended setting. Whatever it drops back to on idle is what it is.