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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: lukieg on September 13, 2011, 10:26:31 pm

Title: manifold or ported vacuum?
Post by: lukieg on September 13, 2011, 10:26:31 pm

  427 td big block. I recently decided to swap the vac canister to ported , and I had it running on full manifold... it seems to run better on ported.. to me this makes no sence..how can this be?

Title: Re: manifold or ported vacuum?
Post by: muddpuppy01 on September 14, 2011, 07:36:32 pm

some like ported some like manifold only difference between the two is ported has no vacuum during idle once you crack the thottle you may get a few hg difference for a small portion then the level off to the same until wot were they are near zero

Title: Re: manifold or ported vacuum?
Post by: VileZambonie on September 14, 2011, 07:43:04 pm

Auto trans? You may end up with less stable idle and hotter idle temps. Whatever gives you the best results. It really depends on your combo and where you have the timing set.

Title: Re: manifold or ported vacuum?
Post by: VileZambonie on September 14, 2011, 07:44:00 pm

Also check to make sure it's working properly.