Need Holley carb help!!!

[1972CST]

I just got done rebuilding an old Holley 600 vac. secondaries to put on a 350 and realized there are not any vacuum ports on the carb anywhere. Has anyone ever run into this? The list #is 1850, under that is 2B1. The only other # stamped on the choke horn is 5752426. Any help would be greatly appreciated.

[johnnywagon]

An 1850 should be your basic 600 manual choke holley. At minimum there should be two vacuum ports in the base plate (one large in the back & one small in the front) and one in the metering block.

Are maybe the holes there but the pressed-in brass fittings gone? Maybe the base plate and or metering block have been changed?

You can always get an under-carb-spacer with a vacuum fitting as a last resort.

[1972CST]

I have e-mailed Holley's tech. dept twice and they wont reply. Maybe this thing is some kind of marine carb or something... anyway I am going to get another 600 from a buddy and get this motor in.

[hgs_notes]

You don't have to use vacuum ports from the carb, you can use a fitting in the manifold just behind the carb. The only vac line I'm running to my holley is for the distributor advance, just cause it was there.

[1972CST]

Dont you need ported vacuum from the carb for the vac advance on dist? Thats the only way I have ever ran it or seen it ran.

[hgs_notes]

The vacuum you see at the base plate of the carb is pretty much the same as that from the intake just behind it. As said before, you could get a spacer with a port, or just drill you'r own in a spacer if you don't feel comfortable with running off manifold vacuum.