Someone help me understand this, Intake opening to throttle body opening

from6to8 · Jul 11, 2025

When it comes to your intake having a certain opening and getting a certain size meter. When I started buying parts back when I did my first real decent comb back in 05, I didn't know much lol. Basically right now I'm not really asking for advice on what to get, but rather say for instance I just read that a Systemax 2 has a 75 mm opening but necks down to a 65 or 70. I'm assuming no matter what tb you get it will bolt up to any upper intake ma I correct? I'll either get a performer 2 or the holley for the 331 and I already have a 70 bbk that I bought new.

Will a 70 tb bolt up to a 5.8 TFS R 90 mm? I know you won't put it on there but just curious.

Noobz347 · Jul 11, 2025

Some big-bore TBs (especially 90mm and above) use a different bolt pattern — often modeled after the 5.4L Lightning/Modular bolt pattern, and that won’t match a standard 5.0/351W EFI intake without an adapter or custom flange.

You can usually go from 55mm to 75mm throttle bodies without issue, bolt-on.

from6to8 · Jul 11, 2025

Noobz347 said:
Some big-bore TBs (especially 90mm and above) use a different bolt pattern — often modeled after the 5.4L Lightning/Modular bolt pattern, and that won’t match a standard 5.0/351W EFI intake without an adapter or custom flange.

You can usually go from 55mm to 75mm throttle bodies without issue, bolt-on.

Gotcha. And so me using the bbk 70 on a systemax 2 shouldn't be an issue then

Noobz347 · Jul 11, 2025

From the Anderson Ford Motorsports website:

(Requires adapter for use with 94-95 throttle bodies)

Holley says:
This Ford EFI passenger car manifold was developed by Holley for its SysteMax II Ford performance package. Don't be fooled by its California emission-legal designation. This manifold will flow like no other street/strip manifold. It's fully machined and ready to bolt down on any engine.
* 2000-6500 RPM power band
* Retains stock injector and water outlet locations
* External EGR passage maximized port and runner sizes
* Maximum unrestricted airflow
* Lower manifold parts match up to Holley cylinder head
* Special shiny finish

We say:
The SysteMax II intake manifold is the best we have ever tested to 6500 rpms for 302/331 c.i. natural aspirated combinations.
For forced induction the SysteMax II intake manifold with 302/347 c.i. combinations is one of the best if not the best up to 6700rpms.

SysteMax II intake manifolds is the most used intake in NMRA Pure Street and Renegade classes.

Tested on Mustang with DSS short block, Twisted Wedge heads, Anderson N-61 camshaft,
Bassani 1 5/8 to 1 3/4 step tube headers, Anderson AF-0112C Power Pipe 77mm Pro-M

Run 018 Ford Racing Cobra Intake
Run 012 Edelbrock Perfomer RPM intake
Run 035 Holley SysteMax II intake

Only change between dyo pulls was intake
Run 043 Trick Flow Track intake
Run 059 Holley SysteMax II intake

from6to8 · Jul 11, 2025

Noobz347 said:
From the Anderson Ford Motorsports website:

(Requires adapter for use with 94-95 throttle bodies)

Holley says:
This Ford EFI passenger car manifold was developed by Holley for its SysteMax II Ford performance package. Don't be fooled by its California emission-legal designation. This manifold will flow like no other street/strip manifold. It's fully machined and ready to bolt down on any engine.
* 2000-6500 RPM power band
* Retains stock injector and water outlet locations
* External EGR passage maximized port and runner sizes
* Maximum unrestricted airflow
* Lower manifold parts match up to Holley cylinder head
* Special shiny finish

We say:
The SysteMax II intake manifold is the best we have ever tested to 6500 rpms for 302/331 c.i. natural aspirated combinations.
For forced induction the SysteMax II intake manifold with 302/347 c.i. combinations is one of the best if not the best up to 6700rpms.

SysteMax II intake manifolds is the most used intake in NMRA Pure Street and Renegade classes.

Tested on Mustang with DSS short block, Twisted Wedge heads, Anderson N-61 camshaft,
Bassani 1 5/8 to 1 3/4 step tube headers, Anderson AF-0112C Power Pipe 77mm Pro-M

Run 018 Ford Racing Cobra Intake
Run 012 Edelbrock Perfomer RPM intake
Run 035 Holley SysteMax II intake

Only change between dyo pulls was intake
Run 043 Trick Flow Track intake
Run 059 Holley SysteMax II intake

would've been nice if that was a performer 2 to see how they stacked up lol. Let me see if there are some comparisons?

70 bbk that I have fine to use with the systemax 2?

Noobz347 · Jul 11, 2025

from6to8 said:
would've been nice if that was a performer 2 to see how they stacked up lol. Let me see if there are some comparisons?

70 bbk that I have fine to use with the systemax 2?

Look around. Go dig up the specification for the intake and see what it says.

from6to8 · Jul 11, 2025

Noobz347 said:
Look around. Go dig up the specification for the intake and see what it says.

just doing a quick search on google it looks like it will bolt right up. I read where one said 75+ might require some work

AeroCoupe · Jul 11, 2025

I have a Performer RPM II on my 331 and run a BBK 70mm throttle body so yes it works with no issues. Lower has been ported and has been gasket matched to the ported heads.

from6to8 · Jul 11, 2025

AeroCoupe said:
I have a Performer RPM II on my 331 and run a BBK 70mm throttle body so yes it works with no issues. Lower has been ported and has been gasket matched to the ported heads.

i know it would work with the rpm 2 as I have that setup on my 302 as well. With the Systemax 2 I wondered earlier when I googled somehthing and it said the Sys 2 has a 75 mm opening. It seems it will bolt right up and work even with the sys 2 and some have said even if it's 75, it's tapered to a 65 or 70. I've read some saying it's a 70 opening though

from6to8 · Jul 11, 2025

AeroCoupe said:
I have a Performer RPM II on my 331 and run a BBK 70mm throttle body so yes it works with no issues. Lower has been ported and has been gasket matched to the ported heads.

what's your 331 setup again and what did you make at the wheels? What rpm are you running it to, ect? Mostly street car or track?

AeroCoupe · Jul 11, 2025

370 at the wheels at 6400 rpm. Peak torque was about 1000 rpm lower. Hasn't seen a track in years.

11:1 and stock block. Ported Edelbrock Performer RPM heads with a very solid valve train. The only think in the fuel system that is stock are the injector rails. Its a lot of stuff and I have posed it several times so a quick search will find more details.

from6to8 · Jul 11, 2025

AeroCoupe said:
370 at the wheels at 6400 rpm. Peak torque was about 1000 rpm lower. Hasn't seen a track in years.

11:1 and stock block. Ported Edelbrock Performer RPM heads with a very solid valve train. The only think in the fuel system that is stock are the injector rails. Its a lot of stuff and I have posed it several times so a quick search will find more details.

I will check it out. Yeah with 370 at the wheels that's no small numbers for a 331 so yeah maybe my builder is right and saying it ain't always everything has to be big but proportionate. You must be have a decent sized cam also

AeroCoupe · Jul 11, 2025

Ed Curtis custom grind. Cam was selected with all of the other parts mentioned so Ed optimized the cam. You need not get hung up on numbers and just let your guy do his thing. It sounds like he knows what he is doing and you are comfortable with his abilities. He will find a block and then it will be downhill from there with the build.

from6to8 · Jul 11, 2025

AeroCoupe said:
370 at the wheels at 6400 rpm. Peak torque was about 1000 rpm lower. Hasn't seen a track in years.

11:1 and stock block. Ported Edelbrock Performer RPM heads with a very solid valve train. The only think in the fuel system that is stock are the injector rails. Its a lot of stuff and I have posed it several times so a quick search will find more details.

Well I have heard some say a search function sucks I can't remember if it's this form or my Giants form or maybe another mustang for him lol. Anyway I searched all your content all your threads start and so obviously 2025 going back to 2004 and I don't see anything specifically about your setup maybe it's something within one of those threads but I didn't see a title saying anything about my 3:31 setup or anything of that nature.

So whenever you get time if you know for sure there's somewhere or some particular post or something if you do a search post a link or let me know what to search for specifically and I will check it out.

AeroCoupe said:
Ed Curtis custom grind. Cam was selected with all of the other parts mentioned so Ed optimized the cam. You need not get hung up on numbers and just let your guy do his thing. It sounds like he knows what he is doing and you are comfortable with his abilities. He will find a block and then it will be downhill from there with the build.

True. I was just curious as to yours

AeroCoupe · Jul 11, 2025

I did the same thing and I guess it just feel like I have listed everything in one place but its all over the place in a lot of threads.

Short Block
Stock 302W block
SCAT Series 9000 cast pro stock crank
Probe Street Fighter main girdle
Probe SRS forged pistons
Probe 4340 "H" beam rods
Melling oil pump (blue printed)
Canton 7 qt road race pan and pickup tube
FTI custom grind cam
Motorsport M-6500-R302H roller lifters with stock spider and "dog bones"
Comp Cams double roller timing chain
Motorcraft water pump

Induction
Edelbrock Performer RPM heads (2.02/1.60)
Manley severe duty valves
Manley titanium keepers
Manley tool steel retainers
Isky 8005 springs
Scorpion 1.6 stud mount roller rockers
ARP rocker studs
Jomar Pro-Model rocker girdles
Edelbrock Performer RPM II upper and lower intakes
lower intake is ported and port matched to the cylinder heads
lower intake and upper intake are port matched
1" spacer is matched to upper and lower
BBK 70mm throttle body with 70 mm EGR spacer
Custom cold air kit:

So it goes from the 70mm (roughly 2.75" ID and 3"+ OD) to some 3.5" aluminum tube via a 3" x 3.5" 60deg elbow. Next is a 3.5" coupler to a 2001 Mustang GT 80mm MAF which has a 4" inlet and 3.5" outlet. I bought a 4" adapter to take the inlet of the MAF from bolt on to slip on so I needed a 4" x 3.5" coupler to adapt the 3.5" inner fender cold air pipe and plate from a BBK 1557 cold air kit to the MAF. Last on the list is a conical K&N air filter in the inner fender.

Exhaust
BBK 1-5/8" equal length headers with the welds on the primaries cleaned up and the ball on the collector opened up
2-1/2" off road X-pipe
2-1/2" cat back with Flow Master 2 chamber mufflers

The fuel rails are stock and it has 42 lb/hr Ford (Bosch) injectors, aftermarket 6AN feed and return lines, stock fuel filter, Pro-M fuel pump hanger, Walbro 255 lph pump. Pump has been rewired and has a dedicated relay and feed directly from the battery. Was getting voltage fluctuations using the stock wiring which affects fuel pressure stability.

Ignition is an MSD-6AL, MSD coil, stock distributor (rebuilt some years ago with all new electronics), Motorsport 9mm wires, and Autolite plugs.

Hopefully that give you and idea of what all I have tied up in the build. It idles great, part throttle is good, destroys the Nittos, and fuel mileage is dependent on my attitude that day.

from6to8 · Jul 11, 2025

AeroCoupe said:
I did the same thing and I guess it just feel like I have listed everything in one place but its all over the place in a lot of threads.

Short Block
Stock 302W block
SCAT Series 9000 cast pro stock crank
Probe Street Fighter main girdle
Probe SRS forged pistons
Probe 4340 "H" beam rods
Melling oil pump (blue printed)
Canton 7 qt road race pan and pickup tube
FTI custom grind cam
Motorsport M-6500-R302H roller lifters with stock spider and "dog bones"
Comp Cams double roller timing chain
Motorcraft water pump

Induction
Edelbrock Performer RPM heads (2.02/1.60)
Manley severe duty valves
Manley titanium keepers
Manley tool steel retainers
Isky 8005 springs
Scorpion 1.6 stud mount roller rockers
ARP rocker studs
Jomar Pro-Model rocker girdles
Edelbrock Performer RPM II upper and lower intakes
lower intake is ported and port matched to the cylinder heads
lower intake and upper intake are port matched
1" spacer is matched to upper and lower
BBK 70mm throttle body with 70 mm EGR spacer
Custom cold air kit:

So it goes from the 70mm (roughly 2.75" ID and 3"+ OD) to some 3.5" aluminum tube via a 3" x 3.5" 60deg elbow. Next is a 3.5" coupler to a 2001 Mustang GT 80mm MAF which has a 4" inlet and 3.5" outlet. I bought a 4" adapter to take the inlet of the MAF from bolt on to slip on so I needed a 4" x 3.5" coupler to adapt the 3.5" inner fender cold air pipe and plate from a BBK 1557 cold air kit to the MAF. Last on the list is a conical K&N air filter in the inner fender.

Exhaust
BBK 1-5/8" equal length headers with the welds on the primaries cleaned up and the ball on the collector opened up
2-1/2" off road X-pipe
2-1/2" cat back with Flow Master 2 chamber mufflers

The fuel rails are stock and it has 42 lb/hr Ford (Bosch) injectors, aftermarket 6AN feed and return lines, stock fuel filter, Pro-M fuel pump hanger, Walbro 255 lph pump. Pump has been rewired and has a dedicated relay and feed directly from the battery. Was getting voltage fluctuations using the stock wiring which affects fuel pressure stability.

Ignition is an MSD-6AL, MSD coil, stock distributor (rebuilt some years ago with all new electronics), Motorsport 9mm wires, and Autolite plugs.

Hopefully that give you and idea of what all I have tied up in the build. It idles great, part throttle is good, destroys the Nittos, and fuel mileage is dependent on my attitude that day.

Nice list and appreciate the time and looks like a well put together combo. Are you on any of the facebook groups?

AeroCoupe · Jul 12, 2025

Hell to the no. Cannot stand FB.

Noobz347 · Jul 12, 2025

This is where people go to debunk what they learned on bookface.

from6to8 · Jul 12, 2025

AeroCoupe said:
Hell to the no. Cannot stand FB.

Lol lol

from6to8 · Jul 12, 2025

Noobz347 said:
This is where people go to debunk what they learned on bookface.

Lmao

Someone help me understand this, Intake opening to throttle body opening

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

There's suction so I used that end O_O

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

There's suction so I used that end O_O

lube between the nut and the face. I know my lubes

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

There's suction so I used that end O_O

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