Help understanding GM vacuum advance codes

[BCreekDave]

The 2 numbers are the max advance built into the can.

More than you want to know about this is here:

https://www.crankshaftcoalition.com/...ance_Specs.pdf

The only other thing I will add is always obey the rule and the rule is always use non-ported vacuum.

[novadude]

Originally Posted by BCreekDave

The only other thing I will add is always obey the law and the law is always use non-ported vacuum.

Laws are made the be broken. Use what works best. On my car that is ported.

Ported was around since way before anyone ever thought about emissions. Don't believe all the garbage that gets regurgitated on the 'net about ported being for emissions only.

[Flying Undertaker]

I have a May 1971 Delco TBA Parts Manual showing vacuum advance unit Delco part D 1328 for 70 Buick Special/ Skylark 350 v-8 Hi-compression as distributor # 1112006. It correlates to GM part #1116163. I hope this helps. Don.

[ScottG]

Originally Posted by Flying Undertaker

I have a May 1971 Delco TBA Parts Manual showing vacuum advance unit Delco part D 1328 for 70 Buick Special/ Skylark 350 v-8 Hi-compression as distributor # 1112006. It correlates to GM part #1116163. I hope this helps. Don.

Thanks to all . I found one for $ 299.00 . Then I found one for $ 68.00 . Then the winner at $ 29.00 Evilbay search .

[John Brown]