I'm not sure how accurate this info is on the stealth head flow numbers out of the box, but I found this Hot Rod article where max flow was only 158.5 @ 0.500"
http://www.hotrod.com/articles/mopp-1205-big-block-cylinder-head-testing-flow-charts/

This is what my stealth heads flowed with just a bit of hand porting (gasket match, bowl blending, and valve job.) Not a huge improvement like CNC porting, but basically just cost me some time and the money for the valve job (and extra to flow the head just to see where it was at.)

Lift Intake Exhaust
0.100" / 82 / 81
0.200" / 157 / 127
0.300" / 221 / 151
0.400" / 260 / 174
0.500" / 278 / 190
0.600" / 283 / 200
0.700" / 289 / 211
0.800" / 289 / 215

I posted this way back in Jan, 2013 when I was putting the engine together.
https://board.moparts.org/ubbthreads/ubbt...tml#Post1024402

That's good info. Do the stealths really flow that poorly at .500?? That's really bad, even on the exhaust side.

The flow bench that my heads were flowed on is an older SF-110 model. I think the cylinder bore size was only 4.25". Not sure what entry radius, if any was used?
I have had 4 heads flowed on that machine, so I just compare what the different heads flowed, and the last 3 seemed reasonable, if not a bit low. The last head flowed at that shop were the Trick Flow 240's and the results were all messed up, not sure if something was going wrong with the test or machine, but the numbers were way low. Took the heads to another shop with a newer SF-1020 flow bench and the flow results were very close to the advertised ratings from Trick Flow.

I am curious as since I put my eng in my 63 together in 2011 I have not looked hard at bigblock heads. And I was curious if the Trick Flows use raised exh ports or standard height exh ports ? I really have not looked into them as I have no plans to change anything big on my car. I do know in 2011 when I bought aluminum heads I went with the basic Indy SEZ heads I bought from Dwayne Porter and he sold them to me for a good reasonable price. There was no Trick Flow heads in 2011 when I built my 493. Dwayne opened up the intake ports to max wedge size as I figured why not in case I want to step it up some later. But I liked the fact the SEZ heads have standard exh ports and I did not need to buy offset rockers or did not need to use external oiling to the heads and could use standard headers. I wanted to keep my eng build very basic and simple since I drive it a lot on the street. I am curious as to how the Indy SEZ heads compare to the Trick flows in performance and price today ? I don't seem to here as much about the Indy SEZ and EZ heads since the Trick Flows came out. Ron

Ootb stealth from a few months ago vs valve job, back cut, bowl blend.

28”, 4.375 bore, radius inlet plate, no tube on ex

Ootb:
Lift——in/ex
.100—65.7/51.8
.200–134.8/101.2
.300–197.2/135.4
.400–241.2/159.0
.450–248.7/167.1
.500–254.3/174.4
.550–256.1/179.8
.600–256.9/184.2

2 mins(or less) in the intake bowl will get it into the 260’s

Cut seats, back cut valves, blend bowls:
Lift——in/ex
.100—72.1/59.1
.200–147.6/112.2
.300–210.4/144.4
.400–254.3/166.4
.450–267.4/176.1
.500–273.7/185.9
.550–277.5/193.2
.600–280.5/198.1

So, if the theory of 1cfm per 2hp is correct, that small amount of head work may equal a 40hp improvement ?? That's money well spent

Ron - I don't think you could have put together a better working combination for the money. Well done!

On a build where the hp/ci is about 1.1, I don’t think you’d see 2hp/cfm gain.

whats the cost of back cut, valve job and bowl blend?

Starting with new** stealth heads........
-disassemble
-measure guides *
-machine and finish grind seats
-back cut valves
-blend bowls
-flow test one cylinder
-jet wash heads
-test springs
-reassemble heads
——————
$450

*if guides need honing it will be an extra charge

**Used heads will need to be jet washed and bead blasted prior to the seats being cut and bowls blended, and the valves will also need to be cleaned, bead blasted, and refaced..... all of which will add $150 to the total.

Thank you Tony. Ron

I know they are a performace based stock upgrade,but where would the Edelbrock E-Street heads fall in power production here? What are their power to cubic inch levels and limitations? Would they be better for the anticipated street torque levels and driveability with the high axle gear ratio? ...sorry for all the questions!

Power potential wise, the E street is the same as the RPM.
It’s the same casting.

Is it just a smaller chamber ?

They come in 75 or 84 cc versions.

May have been said but why not just cnc your heads and maybe some 1.6 rockers(intake anyway) if you are happy with what you have?

Pulled the trigger on the TF 240's. Man they look nice! Note to self: remember, stay the course, this is not a race car

Even with a mild cam those heads will make the car feel like a race car when you put your foot into it. They really work.

Looking forward to getting it going!

They look good Tony. Very nice choice and good luck with it. Ron