I get a kick out of these head guys who recommend a certain head like this. A 396 bbc came with a 256cc runner and 2.065/1.72 valves. smaller engine with a bigger head so how could a 230cc head be too big?
FWIW I know someone who has a Dart 427 sbc crate engine that runs low 12`s in a street car not set up for the track at all.
I honestly think the heads are killing your chances of seeing anything over 550hp but its really going to depend on the camshaft.
It's not that the 230 cc head was too big for my motor, DART just recommended that because I was highly street driven as well, and staying below 7000 rpm, that the 215cc may be more suited for my combo. According to them, the 215 cc has very similar flow numbers as the 230s in the cam lift range I was looking at. Also they claimed the flow velocity from the 215s was higher in the range I was planning. Therefore, they said they would recommend that head for me.
I also discussed this with a reputable local engine builder and he had similar discussion points.
If I choose, I can always upgrade the head down the road, or have them worked over.
I felt comfortable going with that head combo because I had seen several instances of guys making good power (550+) with the same heads and similar cam combos.
The 215cc will be fine for that motor. From what you've stated that motor will be 95% on the street and there for will live in the 1100-3000rpm most of the time. At that range you'll want as much low end torque which is exactly what a 434 w/215cc heads should have. One caveat is the cam choice is a huge decision. Based on your .550-.600 lift range I'm assuming a hydraulic roller is your cam type. That should work great as long as you don't "over" cam with too much duration. You'll want to pay close attention to stall converter selection and ensure the cam has hit its range 500rpm before IMO and drag racing experience. So for example your cam range is 3000-6500rpm I would suggest the lowest stall for you converter at 3500rpm. If possible I would go to a 3700rpm converter if you can find one. For 10.9 ETs you'll need at lease a 1.60 60 foot time and the car needs to pull hard all the way thru the 1/4 mile. 10 seconds cars perform 10s at the 60' times!!!
I agree with sschevellefan. The 215cc head will work good for the street but a big inch small block loves big heads. It'll start running out of steam before 6000 rpm and for horsepower, you don't want that. That engine should make plenty of torque by default because of the long stroke. The big bore will unshroud the valves and let it breathe upstairs if the intake port will let it. Remember, this engine is in big block territory with it's cubes. Would you recommend that small of a head for a 427 big block? I sure wouldn't.....
I understand the heads are not ideal for making huge power, but I planned this engine out to have good street manners as well as make respectable hp numbers. I personally am expecting between 550-575 hp (and will be happy with that). I know my 10.9 goal is probably a little bit of a stretch, but I will be happy with anything less than an 11.5. I believe I should be able to obtain that number with some tuning.
I was willing to sacrifice some high end power for torque. After all this engine is mostly street driven, with once or twice a month trips to the track.
I would love to build a monster 700+ hp small block but I think it would be less enjoyable for me to drive as often. Plus I purchased this shortblock with the intentions of growing a few years down the road. I know I can take this motor far further than I am now, so I plan to keep this engine growing as the years move on. If that means I get these heads reworked, or new heads later, that's fine.
I love the bracket racing I do no matter how fast I go, so I know this setup will yield me several years of fun!