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Old 04-29-2012, 06:18 PM
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I run this cam in my street 406.

Lock out the distributor's mechanical advance system.
Set the now locked timing at 34 to 36deg BTDC.

Retain vacuum advance, but get a fully adjustable crane vac adv
and dial it in to allow 10 to 12deg of added vacuum advance at high cruise speeds
like on the hiway. Limit the max possible amount of added vac advance at highest manifold vacuum (like during deceleration) to 15deg.

The exact rate of vacuum advance has to be found by drive testing
and adjusting the diaphram spring tension.

use ported vacuum.

Get a 3.5" or 4.5" rated power valve for the carb.
Remove the carb and flip it over and reset the pri and sec
throttle opening at idle so that about .020" to .030" of the idle transfer slot is exposed at idle.

make sure the PCV is hooked up and functional.

The XE284H-10 cam needs a 10" high stall torque converter.
Get a 3500+ stall for max performance.
A stock 2000 stall will not work well at all.
Its way too tight at idle.

It will idle easily at 800-900 rpm in neutal-park
and will idle easily and rock steady at 750-800 rpm in gear and not load up.
It will now idle clean without fluctuation and the throttle response will
be much much better.

If its hard to restart when the einge is hot when using locked timing.
install a simple ignition power interupt switch to kill the spark during engine cranking. Make sure the GM rear starter motor mounting bracket is installed when running locked timing.

Are you using a GM HEI distributor?
Which transmission?

Last edited by F-BIRD'88; 04-29-2012 at 06:26 PM.
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