Offy with holley carb

I dont know if this was talked about before, but I was curious if the people out there who upgraded to a 4 bbl carb and offy 360 intake ran into any issues with the ports on the intake. I noticed even on my original intake, the thermostat has a threaded hole on the housing, so does my new offy intake. what does that go to also, I have a lot of ports that are sealed up, any idea what they are for or if they are used. I am setting up my 225 with this upgrade and noticed all the extra ports. and connecting my 4bbl may be another obstacle with vacuum ports.

 

A picture would help, there are fittings for a water temperature probe and for the heater hoses. There is also a fitting for vacuum to run your heater and fan control.

 

the port on your thermostat goes to your water pump and the other threaded on the intake itself is for heater hose. Mine goes to the water pump too since I have no heater. I suppose i could just plug both of them.

As Mcruff stated, the other one is for the temp probe.

 

you have pictures Mcruff

 

trying to get the picture to load to my computer but its not coming up, you have any pics 47v6

 

see the other two ports plugged on both sides as well

 

mine does no have those 2 plugged ports



the threaded one in the front is for temp sender and the one you are pointing to is for heater that I have just routed to waterpump.

 

Those are merely there for heater taps or temp senders also some water pumps have a coolant bypass hose that goes between the pump and that forward taped pipe fitting at the manifold...........use what you need and plug off the rest........................

I would be more curious about what that nipple is that is coming out of that Jet plate on the carb above the Idle screw? Most times that is plugged off.

 

That's the "Timed Spark" port for the Vacuum advance. Assuming you're talking about the nipple there above the idle mixture screw

 

Yep , but normally only used for emissions/EGR engines.........which this is not?

 

Ummmm, that's where I run the hose off the vacuum advance to on my Dauntless.... Works just peachy.

 

Thats where I run my Vac advance from too. Only gives vacuum when off idle.

 

Glad that works...............I've never seen that before cause on the old original Holley 390 CFM #8007 that I have the EGR port was not there. I picked the vacuum up from the base plate........

 

Early meaning 1970.........that port was added when EGR came along and yes in the later versions like you have it is for vacuum advance. No port there in the early versions.

 

Yeah, Mine is quite a bit newer, and it's not the 8007, it's the 470 Truck Avenger. Although I'm pretty sure most of the Holley's have that ported vacuum nipple now.

 

Shaun, I noticed you painted or powder coated your intake manifold.............I see folks doing this all the time and I understand the need to clean it up , along with everyone's personal preference on it's looks. But from a pure performance standpoint bare unpainted aluminum acts in a very beneficial way to dissipate un-wanted heat in the fuel intake track.......which can lead to a less Horsepower brought on by the less denser fuel charge.