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500" 8-71 15# 11:1 want to be able to push the boost into the 20# plus range without problems. Going in a shovelnose for lake and drag use
 

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Short list? Top or bottom? Other considerations? The price seems right on these bare castings at 660 or so per from summit
 

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They're a littel down on flow for a CNC 355 cc head (especially on the exhaust), but they are also about the strongest castings going.
The PB BB2 Xtra (CNC) is a 355cc, the as-cast non-CNC BB2 Xtra is a 365cc. The one Summit has for that price is the 356cc non-cnc. I'd stay away from that.
I think the 355 is a little on the big side for what you're describing, but I wouldn't lose any sleep over it. I think as 355cc runners go, they have a relatively small cross section which I tend to like.
 

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They're a littel down on flow for a CNC 355 cc head (especially on the exhaust), but they are also about the strongest castings going.
The PB BB2 Xtra (CNC) is a 355cc, the as-cast non-CNC BB2 Xtra is a 365cc. The one Summit has for that price is the 356cc non-cnc. I'd stay away from that.
I think the 355 is a little on the big side for what you're describing, but I wouldn't lose any sleep over it. I think as 355cc runners go, they have a relatively small cross section which I tend to like.
You bring up a couple interesting things here. First the Brodix is one strong casting.
But on the flow thing. ALL Brodix heads with the possible exception of the Head Hunter series seem to be low on flow for the size of the port ACCORDING TO THEIR FLOW NUMBERS, vs others. Are Brodix numbers more realistic than some others, or more conservative, or do the heads actually not have the flow that some others have for relatively similar port size, or is it due to, like you say, a small cross secton for the port size? Always wondered about this.



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My bad they were actually 675 per they are the 2020003. Yes, no, maybe?
I know that Summit's website shows that head as being CNC'c on the spec page, but if you go to Brodix's website you will find out it is not.
Not the first time that Summit has had their specs wrong.
The part number for a Brodix 2xtra CNC head is 2028000 and the price is more like 1400.00.
Thats why I question it when you posted them in the 600.00 range. I was ready to order 3 pair.

LINK: Brodix BP BB-2xtra



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You bring up a couple interesting things here. First the Brodix is one strong casting.
But on the flow thing. ALL Brodix heads with the possible exception of the Head Hunter series seem to be low on flow for the size of the port ACCORDING TO THEIR FLOW NUMBERS, vs others. Are Brodix numbers more realistic than some others, or more conservative, or do the heads actually not have the flow that some others have for relatively similar port size, or is it due to, like you say, a small cross secton for the port size? Always wondered about this.
I trust Brodix's advertised flow numbers more than any, and yes, they have some that are low compared to comparable heads on the market. I think Brodix builds basically two kinds of heads. One is not really intended to run out of the box, the other is. Most of their as-cast heads need a ton of work to flow well, especially in the chambers, but their CNC stuff is right there with most other's, and better that many. This also goes to the point of flow numbers not always being the be-all and end-all of a cyl heads's performance potential. One thing to remember is that everything up to their BB3Xtra series is 26*. Their upper-end heads are some of the best available IMO. I think Brodix also offers more selection of different combinations of port configurations than any other mfgr. They will also work direct with a builder to tailor a casting for specific needs.
 

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Jim, Give Bob Gromm a call (Gromm Racing Heads) 408-287-1301 he's building me a set of Brodix 345's ..... he's been doing heads for a long time and is very good, wouldn't hurt to call if you need some info. Check your PM's
 

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i think the sts-b1 cnc heads look to be the shit, flowing almost 400 cfm 800 lift and 20 cfm less than max flow at 700 lift.:thumb:


I take it you got those numbers from some source other than Brodix. They have them at 379 @ .800 and 374 @ .700.


You have to love the "glass half full guys" You see it as a port that only loses 4 cfm less at .700. I see it as a port that stopped flowing. Not all bad considering some ports fall down as the lift increases past max. But saying the port the port only loses 4 CFM from max is kind of glossy way of saying the port was finished at .700.


Like Steel said, flow isn't everything, specially max flow. I give a little @ .800 to gain alot @ .400.

Still, not a bad numbers for a 305 head. The BB1 is the head that put Brodix on the map. Alot guys would well off with that head compared to what some use to replace stock rectangle port heads with.



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i think the sts-b1 cnc heads look to be the shit, flowing almost 400 cfm 800 lift and 20 cfm less than max flow at 700 lift.:thumb:
The STS BB1 is a great little head...one of the best small rect. port heads on the market right there with the AFR, but like GN said I think you have your flow numbers a little confused.
 

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355

What does everyone think of these heads in the Cnc version? Any good for blown alky?
I am not an engine builder or expert, but I used that exact head on a pump gas 572 and made 837 hp with less than .700 lift on my build. I know, not a blown comparison but they worked good. They were also seconds that I bought directly from Brodix.
 
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