No ported vacum port

Blue67camino · Nov 7, 2001

I am in the process of installing a 3x2 setup on my 454HO (for look's and hood clearance). I just looked at the center carb and it does not have a ported vacuum port. I would like to know if I can switch another metering block into the 4055-1 carb that has a ported vacuum port. I do not know if there is some type of inline valve that I could use in the vacuum line to the distributor to act like ported vacuum. I think my only choice is to disable the vacuum advance and recurve the mech advance in the distributor. The car just run to good with this vacuum advance on the HEI distributor and I drive mostly on the street and just looking for the easy way out. Thanks

Blazer1970 · Nov 8, 2001

Just set it up to run the vacuum advance off full vacuum. This is the best set-up for driveability, performance and economy anyway.

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chev-hell · Nov 8, 2001

or like you said recurve it for no vac. advance, 1 less line to worry about. mine runs 18* initial 36* total HEI daily driven 454, not a prolem.

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1970 SS396 AKA 454/4spd
My Chev-Hell Page
GOLD Member #783
Ft.Worth, Tx
(OO=ss=OO)

Terry krook · Nov 8, 2001

Mine also has been recurved for no vacuum advance. 34 degrees total advance. Seasonal daily driver. No problems

Gene Chas · Nov 8, 2001

Well thats all fine and dandy boys, but the vacuum advance helps light throttle low-rpm cruise immensely, or they wouldn't have put it on in the first place.

With 35 total and 13 vaccum = 48, my 67 tripower ( 3.55 geared) scratches out 17 mpg on the open road. To me, that is worth the advance. Y'all don't do anywhere near that I'm sure.

Check amount of advance. Some stock HEI are for low comp engines and have 20+ degrees. For most BBC's 8-15 is about right. Get it to 10-15 either by using a stop or by buying an $18 Crane vacuum unit. And run it to full vacuum.

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Member #62 Gold/ACES 03112
67 SS396(427-3X2)
Be Big, Be a Builder

Blue67camino · Nov 8, 2001

Thanks for all the inputs, I agree with Gene I am going to get the Crane kit. I messup one time and put the vacuum in the direct port and that baby did not run good at all and that was when I had the small block in her. I do not want to go there again. again thanks for all the input. Jerry

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67 ELCO 454HO
3X2 Tri Power
Team Chevelle #1488

Terry krook · Nov 8, 2001

17+ Gene? I don't think I could get there by shutting it off going down hill. I am going to have to re-think this one. Just goes to prove you are never too old to learn, and I am getting pretty darn old! No grey hair though!! At least when my hair dies, it has the decency to fall out!

No ported vacum port

Blue67camino

Blazer1970

chev-hell

Terry krook

Gene Chas

Blue67camino

Terry krook

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