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Old 04-13-2025, 06:03 AM
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Kenth Kenth is offline
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Quote:
Originally Posted by steve25 View Post
As opposed to years previous to 1970 and except for the 1970 455 HO motor, ported vacuum was not used on all other 1970 Pontiac V8 motors including the 2BBl motors.

The TCS system used full manifold vacuum.

Not sure if you can drill the carb and press in a steel or brass tube.
Not true at all!

1970-71 and 73-74 engines, except 1971 455 H.O., uses the Transmission Control Spark system, TCS.
1971 455 H.O. uses a ported vacuum source with a TVS to control the vacuum advance.
1972 uses the similar Speed Control Spark, SCS.

FWIW
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