horsepower potential af kaase boss 9 heads?

I was woundering how much horsepower these heads would make on a high compression 600ci motor naturally aspirated unported out of the box heads as well as ported? I have always ran sbf so the big blocks are new to me. Thanks in advance for any input.

May I ask what the goal is? rules etc?

I saw where you were selling all your smallblock stuff, where are you from? Gotta watch that Mike D. character.......................

I am from arkansas. The rules are for conventional headed big blocks,638ci limit,cast single four barrel carbs on racing gas,29x10.5 tire.3200lbs race weight,no DFI,aluminum blocks add 200lbs,small blocks can run any style heads and at 2800lbs. You are right about duffy,but he is a good fellow. I have also checked with the rule makers and these heads are legal.

Imagine the crying that will take place if what you say is true lol.

What I am saying is true.

Chevy guys wish they were us................

Well seeing how I made 924 hp from stock P51 heads, I would think unported Boss 9 heads would put you over 1,000. Ported, not sure. Kaase would be the best one to answer that--just call him.

Here is what a 598" TFS A460 deal makes......get you some

Thats impressive. Ported A heads?

Sure they are ported......this has been posted for several weeks on this forum.....where you been?

Wow thats nice. Where is that thread? In proven builds?

psfracer wrote:Wow thats nice. Where is that thread? In proven builds?

General Discussion, last one on the first page.
https://www.429-460.com/t8133-engine

Remember your running a BBF and they'll find a way to screw ya! I'd check and see if Boss9, A460 or C460 heads are even allowed. They might limit you to SCJ's, TF streets or P51's.

full on P51 deal still make um cry lol.

Let us adore you........

big tube mafia..............

The c-460 is not legal,but the kaase boss head is. The record is a 5.29 which is held by a bbc powered new body style mustang,but that time was ran with digital fuel injection which is not legal now.the fastest anyone has been with a carb is 5.38,so that is where I need to be to be competitive.

what about the TFS A head like Lem has pictured? Another thing to consider is how much heavier is the Boss head to a CJ style? but at 3200#'s it may not be a factor.

I am not sure about the TFS A460 head being legal or not. I am just trying to make as much power as I can up front.

The boss heads came on production cars. That is what they are basing there rules off of. The pro stock style boss heads are not legal,just the new kaase boss 9 head

nathan mann wrote:The c-460 is not legal,but the kaase boss head is. The record is a 5.29 which is held by a bbc powered new body style mustang,but that time was ran with digital fuel injection which is not legal now.the fastest anyone has been with a carb is 5.38,so that is where I need to be to be competitive.

i broke out in a rash when I saw BBC and mustang in the same sentance

I've ported a couple of sets of the new style Kaase Boss 429 heads and do have horsepower potential.

One set with epoxy in the intake port for small cubic inches flowed;
Intakes, 2.300 valve; .100=75, .200=157, .300=243, .400=323, .500=383, .600=420, .700=430, .800=432 cfm
Exhaust, 1.900 valve; .100=52, .200=123, .300=169, .400=223, .500=261, .600=290, .700=309, .800=315 cfm

The other set did not have epoxy in the port and flowed;
Intakes, 2.300 valve; .100=74, .200=163, .300=276, .400=356, .500=409, .600=432, .700=430, .800=428 cfm
Exhausts, 1.900 valve; .100=53, .200=127, .300=182, .400=246, .500=282, .600=308, .700=313, .800=315 cfm

I'd say neither set was a "max effort" deal, and I'm anxious to try a bigger 2.350" or even larger intake valve in the intake port. I am guessing that we can get 450 cfm or so out of the intake, we are already at 432 cfm so that doesn't seem out of reason to me. The intake seat will need to be replaced in order to go with a bigger valve according to Claude at CHE Precision. So if you can take those flow numbers and plug them in to some kind of on-line calculator it may be able to tell you what kind of power potential your proposed engine might make. Kaase's cast single plane intake manifold is pretty good, although it still needs to be ported IMO.

Hope this helps,

Charlie Evans