Building a Dart SHP 4.125 with a Callies 6inch rod and a 4 inch stroke. looking at the Dart alum head with 215 runners and 74 cc chambers. I think I will be around 10.8 comp with a .041 head gasket. is this the right head choice. they are around $900 and look pretty good.
What do you think?

 

If I were building a 427 the bare minimum head I'd go with would be afr 220cc.

 

I have the older dart 215 heads ,the new dart heads are suppose to be better .if I redo my 427 ,I want to use the AFR 220 head .you will need a single plane intake ,get 1 with coolant passages at the back of the intake .get the cam after you have all of the other big parts .consider a 4/7 swap solid roller cam .

 

That price is per head. 74cc not available. These have a 75 CC chamber. Better flow. Saves $400 compared to the 220. That can be spent on a AFR Titan dual plane intake that matches the port. Both use the 1206 intake gasket size. The Titan intake will get you extra HP and the combination will improve bottom end and midrange power compared to a 220 head with a single plane. You might give up a little peak HP on the dyno but gain noticeable torque and power where you will use it. If you really want 220 heads the competition ported AFR 210 eliminator flow better numbers than the AFR 220 head for similar money with a smaller port and can be used with the Titan dual plane. Whatever you do make sure you get the springs installed on the heads by AFR to match your cam.
http://www.summitracing.com/parts/af...make/chevrolet
http://www.summitracing.com/parts/afr-4804/overview/

 

Have a look at Profiler

 

The smallest head gm put on a BBC with 3.766" stroke was around 253cc. The largest head was 320cc.

Your SBC has more piston speed then a BBC, therefore it puts more demand on induction.

 

AFR matched a Vic Jr. to my 227 Eliminators ending up with only a 3% loss
I had them flowed with intake on and with the intake off. They did a good job as I can look down the runners and you can see

 

I have Dart 215's on my 406.

 

Look at flow numbers not exclusively Intake port CC. The most flow through the smallest port that meets your power goals is the best option on the street. Port velocity is king in a street application. Otherwise everybody would buy an AFR245. You can roughly figure double the intake flow at max lift of your cam is the HP potential of a given head if everything else in the build is optimally matched for the build. Peak power numbers are great but if that power comes at an RPM you don't see 95+% of the time and the tradeoff is noticable loss of bottom end and midrange throttle response and power is that a good trade? A single plane will make more power. An AFR 245 will make more power. Combined with a cam that pulls to 7500 RPM and 12.5 to 1 compression you will make great peak dyno numbers. Is that your goal?, Sucks on the street, great at the track. I guess the best thing is to ask, what is your budget, What is your intended use (street, street/ strip, all out drag racing, Road course)? What power level are you looking for? What is your anticipated redline? What trans? What rear gear? What is your driving style? What power level can the rest of your drivetrain handle? What fuel is available? The above answers will determine your best options. I was assuming with under 10.8 to 1 mostly street, Street/Strip build with capable drivetrain.

Edit: Answer the above questions and you will get much better info. You have a lot of knowledgeable people responding, give them what they need to help you best.

 

I've built a few 415 - 434 small blocks. What cc dish are you using in this build?

Is that price for bare or complete heads? I have a set of what began as Dart 215 cc. They are a wonderful head compared to the AFR. Better oil flow return and the most important feature of spark plug placement.

I will caution you that the SHP block is only made for 3.750 stroke and requires machining of the pan rails for larger strokes using big bolt rods. It is better to just buy one of the more expensive blocks made for the longer 4 inch stroke

 

Ok thanks,
I want to use the car only on the street. I want to make 500 HP or more. Autotrans built for 600 HP with overdrive (haven't picked the stall converter yet), 377 rear gears. I want to run pump gas. the callies tech guy told me that with 74 cc chamber it would be 10.8:1. I think the pistons are a -5cc. I want something pretty mean but still able to run on the freeway for a Sunday drive.

 

anybody know anything about the profiler heads, great price, but that isn't my only goal.

 

saw a 427 sbc short block for $3250 on Ebay .they listed a 427 sbc with dart aluminum heads for $4400 .I got the port sizes mixed up ,when I mentioned 220 port heads..I am looking at the 210 ,and the 227 AFR heads .you can get the 227 afr heads for $1596 at competition products . I feel a dual plane intake will hurt all power numbers on a sbc with a 4" stroke .like mentioned in another thread ,how much torque can your drive line handle .

 

wow, I don't know how to answer that. Not enough experience. brand new rebuilt rear, best ujoints all new suspension, Bowtie trans good for 600+ hp. sorry that is the best I can answer

 

I am sticking with my recommendation. AFR 210 75 CC chambers (competition ported if you can afford it) with AFR Titan dual plane intake (2500-6500 RPM). I would go with a big lift HR cam something like this http://www.summitracing.com/parts/hr...make/chevrolet
In a 10.8 to 1 427 it should pull 2000-6500 RPM, make close to 600 HP and pull hard all the way to redline.
The AFR Titan has a higher operating range than your typical dual plane intake, makes big power numbers, ports match, not real tall. Sounds like im outvoted here so I'm out.
EDIT: The 210's flow 309 CFM intake and 220 CFM Exhaust @ .600 lift
Competition ported AFR 210 flows 318 CFM intake 235 CFM exhaust @ .600 Lift

 

Thanks for the help!

 

So my question would be when they're comp ported do they retain the same port size?

 

No, and modern CNC porting is the most invasive. You can expect 6 - 20 cc increase. We cc'ed my Dart 215 with factory porting including the 2.08/1.625 valves and i was very near 227cc.

polishing and blending can't gain 20+ cfm of flow

 

The base head is already CNC ported. They flow 9 CFM more on the intake side @ .600 not 20+. Polishing and blending at the right points will get you there. Im sure they are opening up the exhaust side a little but they are only gaining 15 CFM there, not 20+. Darts always run bigger than advertised. Dart 180 is 190+ out of the box. Gasket size is the same on both AFR heads and they are meant to match the Titan intake. Put a set of 227's on it with a $2000 shaft rocker setup and a Victor Jr and a big solid roller if you want. Im just suggesting what I would do on a street, Sunday driver car. As I said I'm outvoted. I'm out!

 

Yes, i agree that some manufacturers have larger ports than advertized to attain the bigger listed flow CFM.