[charles69]

I have a 1969 chevelle ss. 396ci/325 hp. It has a stock cam,performance intake, Mallory Unlite disrtibutor, and a Holley carb(750cfm w/vaccum secondaries. My question is several parts:
1. What is the best way to time it at idle, with or without vaccum hookup.
2. What vaccum connect should I use on the carb for the distributor advanced? The constant at the base plate or the port vaccum higher up on the carb?

Thank you in advanced,
Charles
gold member#135

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[This message has been edited by charles69 (edited 06-16-99).]

 

[67RAT]

CHARLES69
YOU SHOULD ALWAYS DISCONNECT THE VACUUM AD
-VANCE WHEN YOU DO YOUR TIMING.AS FOR WITCH
VACUUM PORT TO USE SO MUCH COMES INTO PLAY
BUT AFTER POWER TIMING MY L-88 SPEC BIG
BLOCK I HAD MINE ON THE DIRECT VACUUM PORT.
SOON AFTER BREAK IN I DEVELOPED A OFF IDEL
KNOCK .MOVED IT TO THE ONE ON METERING BLOCK
AND IT CORRECTED MY KNOCK IM THE DRIVE IT
AROUND THE BLOCK 40 TIMES TO TUNE IT TYPE

 

[RAA]

1. Keep the vacuum advance disconnected.

2. I have a Holly 3310 carb, and the vacuum advance is hooked up to the bottom left hand fitting as you are looking at the carb from the front (i.e., ported vacuum). It works great!

 

[Larry]

The port on the metering block is intended for vacuum advance.