What are these holes in my intake?

[Ypsik10]

Different from my stock 305 intake large front driver side hole? The two holes drivers side next to carb need to be plugged? Same with the one right behind intake in the block..

 

[vkh]

The hole next to the thermostat spot is just an alternative location for you temp sensor, not sure about small blocks but early big blocks used a manifold sensor and didn't have a spot in the heads for one. It's handy if you want to use a fan controller or some self learning EFI without messing with your gauge sensor. Otherwise just get an NPT pipe plug. Now the two holes next to the carb are for the AC mounting bracket, I imagine this is specific to some years but regardless you don't need to worry about plugging them. I believe the back hole is a provision for an oil pressure sending unit, if you are going to mount your sensor somewhere else plug it (also NPT). Now I haven't done too much with sbcs (all my experience is bbc) so take what i say with a grain of salt, someone else will probably chime in to confirm or deny.

 

[theblindchicken]

The hole next to the thermostat spot is just an alternative location for you temp sensor, not sure about small blocks but early big blocks used a manifold sensor and didn't have a spot in the heads for one. It's handy if you want to use a fan controller or some self learning EFI without messing with your gauge sensor. Otherwise just get an NPT pipe plug. Now the two holes next to the carb are for the AC mounting bracket, I imagine this is specific to some years but regardless you don't need to worry about plugging them. I believe the back hole is a provision for an oil pressure sending unit, if you are going to mount your sensor somewhere else plug it (also NPT). Now I haven't done too much with sbcs (all my experience is bbc) so take what i say with a grain of salt, someone else will probably chime in to confirm or deny.

I dont have an edlebrock intake, but I can say that on my stock manifold the oil pressure line is at the very back of the manifold near the coil/distributor.

 

[1973c10]

The one right behind intake in the block is for your oil pressure line for mechanical gauge
or for oil pressure sending unit for electric oil pressure gauge
passenger side - port to heater core if used
driver side - temp sending unit, if you need it
the one right behind the crab is a vacuum port to brakes if you need it

 

[Ypsik10]

cool thanks everyone!

 

[Camar068]

the one right behind the crab is a vacuum port to brakes if you need it

as usual, learn something new every day. Never see a brake booster hooked up to anything but the carb. Thx

 

[theblindchicken]

as usual, learn something new every day. Never see a brake booster hooked up to anything but the carb. Thx

I guess that spot would also work perfect for a vacuum gauge then, huh?

 

[Camar068]

lol never seen an old school vacuum sensor or guage.....I reckon so. Swear they should have made it an option for a "gear heads" package to include vacuum, fuel pressure, trans temp and others I'm missing. It would have carried on if they'd offered the damn thing as a package.

 

[74 Shortbed]

I guess that spot would also work perfect for a vacuum gauge then, huh?

That port was used mainly for the modulator on the tranny, then used for smog garbage and whatever else that can use straight manifold vacuum, so it can be used for a vacuum gauge for sure, just need to add a fitting.

 

[74 Shortbed]

as usual, learn something new every day. Never see a brake booster hooked up to anything but the carb. Thx

Never seen one hooked up there either, but it surely could though..

 

[theblindchicken]

Was thinking it'd be a cool quick spot to use to check for vacuum without disassembling anything else.

 

[74 Shortbed]

Yep it would, that port can be used for anything that needs manifold vacuum, just make a tree, lol..

 

[theblindchicken]

Yep it would, that port can be used for anything that needs manifold vacuum, just make a tree, lol..

Keep stacking 3-way and 4-ways til it pops outta the hood? Hahaha

 

[74 Shortbed]

keep stacking 3-way and 4-ways til it pops outta the hood? Hahaha

lol....

 

[highdesertrange]

the oil pressure port on the back of the engine is on the block not the intake manifold. highdesertranger