HELP!!!!

[NastyRay]

How do you tell the difference?

The Holley high rise was a good price and I thought it was the right fit now I’m questioning myself.. should I just get an Edlebrock performer? It’s a kick in the nuts cause it was not cheap

 

[Grumpy]

The Holley high rise was a good price and I thought it was the right fit now I’m questioning myself.. should I just get an Edlebrock performer? It’s a kick in the nuts cause it was not cheap

This is where I said to verify the intake manifold gaskets. Lay them on the head and observe if the gaskets are able to seal around the entire intake port of each port.
Big Block Chevy heads come in many configurations: round port (yucky old grain truck and school bus stuff,) oval port (much better for low to mid-high horsepower engines, with many easily reaching 550hp these days,) and rectangular port (the stuff of muscle car legends and the pinnacle of today's big blocks.)
Any mismatch is absolutely verboten!
Each step in every last mechanical task, be it replacing a tire, rewiring an ECM connector, or rebuilding an engine MUST BE DELIBERATE AND HAVE ABSOLUTE ATTENTION TO DETAIL. Mistakes happen all on their own without help.

Tip: If you are looking at a particular gasket, and it isn't clear which way it is to be installed, look for a part number on it. Part numbers on gaskets are either placed up, facing out or facing forward. Even after 35 years as a journeyman, I still look for the instruction sheet and see if the print date is recent - as if someone has taken the time to rewrite and print off a new set of instructions for the customer, it is worth reading to see if there have been some changes in procedure.

 

[nvrenuf]

Do you have a part number for the intake? It might be on it.
Do you know what heads are on the motor? If not and you want to find out, pull a valve cover the number will be a raised casting +/- 8 numbers long.

 

[NastyRay]

This is where I said to verify the intake manifold gaskets. Lay them on the head and observe if the gaskets are able to seal around the entire intake port of each port.
Big Block Chevy heads come in many configurations: round port (yucky old grain truck and school bus stuff,) oval port (much better for low to mid-high horsepower engines, with many easily reaching 550hp these days,) and rectangular port (the stuff of muscle car legends and the pinnacle of today's big blocks.)
Any mismatch is absolutely verboten!
Each step in every last mechanical task, be it replacing a tire, rewiring an ECM connector, or rebuilding an engine MUST BE DELIBERATE AND HAVE ABSOLUTE ATTENTION TO DETAIL. Mistakes happen all on their own without help.

Tip: If you are looking at a particular gasket, and it isn't clear which way it is to be installed, look for a part number on it. Part numbers on gaskets are either placed up, facing out or facing forward. Even after 35 years as a journeyman, I still look for the instruction sheet and see if the print date is recent - as if someone has taken the time to rewrite and print off a new set of instructions for the customer, it is worth reading to see if there have been some changes in procedure.

Hey thank you I really appreciate it. And your absolutely right about attention to detail and being meticulous. It’s something I’m learning…(the hardway) but I’m learning. This is my first full build and I’m so thankful for guys like you to help me when I am stuck.

 

[NastyRay]

Do you have a part number for the intake? It might be on it.
Do you know what heads are on the motor? If not and you want to find out, pull a valve cover the number will be a raised casting +/- 8 numbers long.

I’m going to do that first thing in the morning when I get to my shop. That way I can verify I am not trying to put the wrong part on

 

[NastyRay]

I’m going to do that first thing in the morning when I get to my shop. That way I can verify I am not trying to put the wrong part on

chevy head 346236 and Holley. Strip dominator intake

 

[nvrenuf]

Can you find the actual part number of the intake?

Big block heads and intakes come in several port shapes and sizes (based on the head type) which requires the intake to match and will not always work if the intake vs head port types don't match.

 

[nvrenuf]

chevy head 346236 and Holley.

346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports

Those heads are "peanut port" type heads, meaning they have small intake ports / runners and flow decent up to about 4500 rpm. They can be made to work better with port work and valve size changes. They have large combustion chambers so if you are running stock or flat top pistons the compression ratio is going to be around 8:1.

Unless you specifically purchased it for those heads, I'd be surprised if that intake is for peanut port heads.

 

[85K304SPD]

Find a drag racer or boat racer and sell them that intake and get you a stocker or single plane of some sort and make sure it fits correctly and go from there on tuning your new motor for what it is, a truck motor, not a drag race motor. You will be much happier with the drivability vs. the top end horsepower.

 

[NastyRay]

346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports

Those heads are "peanut port" type heads, meaning they have small intake ports / runners and flow decent up to about 4500 rpm. They can be made to work better with port work and valve size changes. They have large combustion chambers so if you are running stock or flat top pistons the compression ratio is going to be around 8:1.

Unless you specifically purchased it for those heads, I'd be surprised if that intake is for peanut port heads.

Can you by any chance tell me what damn intake will work. Something through autozone cause that is where my commercial account is

 

[Bextreme04]

Can you by any chance tell me what damn intake will work. Something through autozone cause that is where my commercial account is

Go on facebook marketplace and search for BBC intake manifold. There's an oval port one down here in Salem for $180. The performer 2.0 is the go-to oval port BBC street intake.

Where did you get this crate motor from? Any specs on it? If you got it from autozone.... you are going to want to tear it down and inspect everything, because there are some major horror stories of mismatched parts and loose/stripped bolts.

What cam is in it?

 

[Bextreme04]

Also, the holley intake part number is on the underside of the manifold. If its a 300-4 it's for a standard deck, oval port. 300-5 is standard deck, rectangular port. I dont know if they make a tall deck strip dominator, but they might.

A standard deck BBC will be 9.8" from crank centerline to cylinder head mounting surface(deck). Tall deck is 10.2".

A block casting number will tell you if it is a tall or standard deck.

 

[NastyRay]

Can you by any chance tell me what damn intake will work. Something through autozone cause that is where my commercial account is

Go on facebook marketplace and search for BBC intake manifold. There's an oval port one down here in Salem for $180. The performer 2.0 is the go-to oval port BBC street intake.

Where did you get this crate motor from? Any specs on it? If you got it from autozone.... you are going to want to tear it down and inspect everything, because there are some major horror stories of mismatched parts and loose/stripped bolts.

What cam is in it?

 

[Bextreme04]

Yep, notice the operating RPM band on those. Your holley intake, even if it didn't have a leak, would be killing the low end torque on your peanut port heads. Without significant modifications, the peanut ports are all done by about 4500rpm. The one down here in Salem looks to be the standard Performer 2-0, which is the one you want. If you had car large oval port heads, in a lighter weight car, I would recommend the RPM air-gap manifold.

Did you swap in a different cam? What cam did your motor come with? Where did you get the motor?

 

[nvrenuf]

Go on facebook marketplace and search for BBC intake manifold. There's an oval port one down here in Salem for $180. The performer 2.0 is the go-to oval port BBC street intake.

I don't have any experience with peanut port heads, do the oval and peanut port designs interchange?

@NastyRay no one will be able to make intake recommendations without knowing more about the motor - what cam (part # or actual specs) you're using will dictate the rpm range which in turn effects which intake works best.

Just to say it out loud - For me, I am agreeing that the current intake MAY NOT be the best selection depending it's positive ID. I am NOT saying I think the intake design is the root of the problem you posted about, especially since you were able to effect how the engine runs by spraying around the carb base.