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Discussion Starter #1
Curious what heads would be the best flow match to an unmodified SysteMAX II intake on top of a 302 cube engine.
 

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Discussion Starter #2
Nobody?

Doing some research last night, I'm thinking that a set of ProMAXX 180's would be a good match.
 

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Way back when, the Holley Systemax II kit came with Systemax heads which were effectively Twisted Wedges. See Ed's correction below.

All you have to do is find out what the intake flows and compare that to what aftermarket heads flow.
 

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Way back when, the Holley Systemax II kit came with Systemax heads which were effectively Twisted Wedges.

All you have to do is find out what the intake flows and compare that to what aftermarket heads flow.
Nope -

Those early Systemax top end packages used a Brodix ST5.0 or Edelbrock/AFR cast head. No Twisted Wedges.

This is a set of the AFR based Holleys I ported a while back.



 
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The Brodix casting they did for Holley.



Real Brodix ST5.0 versus AFR/Holley

 
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Discussion Starter #8
Why did your research say they would be a good match?
I dug around and turned up a post from TMOSS that said the SMII flowed around an average of 260ish cfm. The ProMAXX website says the 180cc head flows around 260ish at around 0.550" lift. So I suspect that neither would really inhibit the other. Couple with a cam that compliments that lift range with duration that's not crazy and it should be a decent package OTS package for a street car.
 

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Just wondering. I have not seen or read about many combos. There was one guy on facebook who has ridiculous dyno numbers, but His slip is so far off. Another has a very fast turbo car.
 

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Discussion Starter #11
I have AFR 185's they seem to match up to the intake very well
Please tell me more about your combo. I have a 331 with AFR185 Outlaw (1st generation) heads. It has a TF R intake (not the box) and a SMII on the shelf. I keep waffling between swapping the SMII onto the car and leaing it as is. The TF has to come off to address an oil leak, so it's just a question of which one goes back on.
 

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SysteMax II 12345678AvgMinMaxSpreadTest "
Stock U+L CFM2422722732602302582632622582302734328"
 

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Discussion Starter #14
SysteMax II12345678AvgMinMaxSpreadTest "
Stock U+L CFM2422722732602302582632622582302734328"
Can one "fix" a bit of the flow of #1 and #5 to get it closer to balancing with the other ports? Would that not help fuel distribution and make the engine run a little better? More efficiently?

It seems 1 & 5 would run more rich than than others since it would get fuel based on the MAF values and the cylinders would get notably less air than the other cylinders. It seems that if one could reduce the cfm spread from 43 to say 13 that would be a substantial improvement.
 

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Can one "fix" a bit of the flow of #1 and #5 to get it closer to balancing with the other ports? Would that not help fuel distribution and make the engine run a little better? More efficiently?
They are the longest and have a dog leg so to compare them to the shorter, straighter runners is akin to comparing a Twisted Wedge head to an Edelbrock Performer. They can be "fixed" as you say but the key is the entire inlet tract from throttle body to valve seat. With different length tracts and runner cross sections, you would be chasing your tail trying to "flow balance" the combination.

As for running better, who says having two different pressure waves is bad for a street based engine? ;)
 
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Please tell me more about your combo. I have a 331 with AFR185 Outlaw (1st generation) heads. It has a TF R intake (not the box) and a SMII on the shelf. I keep waffling between swapping the SMII onto the car and leaing it as is. The TF has to come off to address an oil leak, so it's just a question of which one goes back on.
Mine is also a 331. I have the newer renegade heads, Anderson n61 cam, sm II intake, 75 mm tb, 36lb injectors, longtubes etc. I will say it runs very good on the street, it really seems to pull hard in the 6000 to 6500 range. Coming from my old combo which was the older afr heads and street heat intake, it pulls MUCH harder up top but doesn't quite have the low speed response of my old setup. I switched after hearing everyone say the systemax is a tough intake to beat. I will say I was under the impression that the Trick Flow R actually does flow better...
 

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I will add something to what Ed said - when you bolt an intake to the head and add length, it changes those flow bench numbers and they tend to come closer together and lower......You can get an idea by looking at the head flow data of the head you are using. As always, I will say that we don't race flow benches and sometimes something that should "not work" does very well. You must look at the entire car setup, not just the engine.
 
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