I know the 240 and 270 heads flow identical from.100" to .300" and then start to change. It isn't until .600" you really see some substantial increases for the 270's vs 240's.

I'm going to investigate getting the stealth's ported with new springs, locks and retainers and see how much i'll be into them compared to if I sold them and bought some trickflows. I'm thinking I'll end up having the same total amount of money in a set of heads either way even if I take a few hundred dollar hit on the stealth's.

That is a interesting thought on the about the cross section to cubic inch ratio. I'm not engine builder and do not know science to building an engine but that makes sense to me at face value. I'm sure there is more to this!

AndyF would you have dyno sheets you could post showing the 240's vs 270's when you did the back to back pulls? It would be interesting to see the slower port velocity of the 270's down low in the rpm's and to also see where peak torque and hp happened for each head. I am surprised the engine didn't make more hp on average earlier and at a greater number since you had some pretty serious lift without a ton of duration on that cam. Like I said I'm not a engine builder so that may seem like a dumb statement! It is the air velocity that is keeping power so close to with each head correct?

ProSport - That is a impressive run! What weight is your car and what trans setup are you running and what is your tire size? Please divulge any more details you can on your ride if you can! Wicked car!

Thanks, it's a 3300# Duster with me in it.
275/60/15 drag radial, bone stock suspension, one new leaf added to each spring as they were sagging.
727 trans, 9.5" dynamic street converter, 8.75 rearend with Yukon nodular center section and stock 3.23 gears, Moser axles and spool.
Small 1.75 headers, mechanical water pump and fan, never runs hot. Indy intake with pro-systems 950 carb.

Without any specific horsepower or ET goal, I’d say you could achieve good results with either std or MW port.
If I were starting from scratch, I’d probably lean towards the 270’s and run the Indy 2D opened up to match the heads.

My combo is wilder than your looking to build, but in my opinion it works good on the street. 67 Barracuda, 3300#, 512@11.25:1,270@50 solid flat, 5200 8", 4.30/28" tire. Vacuum idling in park is 9" and 7" in drive. I'm using the MW Edelbrock victors with CNC by Hughes Engines. Heads flow 356 from .600 on up and port measures 330cc. It will soon be getting a 3.73 gear as i think it can handle it just fine. Haven't been to the track yet,but i am expecting easy mid 10's and should go low 10's on drag radials. Currently using Hoosier QTP and i can break those loose at 45MPH in 3rd gear. Plenty of grunt for the street and resently drove 60 miles to a car show in 92* humid weather with no issues other than it was very hot inside the car. I would go the the 270 head with not much to loose down low. 512's make alot of torque anyway with that 4.25 arm. One other thing, my 8" 5200 vert drives like a common 3500 stall or better. Got it from Dynamic and refreshed by Lenny. Very nice piece. Hope this helps.

Kind of reminds me of the article way back in the dark ages when Chrysler Power put their set of -1 heads on their dually and reported favorably.

I had three different sets of heads on my old pump gas Duster stroker motor, a set of 906 ported big valve heads, a set of CNC ported Eddy RPM heads. I used the same intake and carbs on both of those, I saw .2 ET (10.69 to 10.49) and 3.2 MPH(124.5 to 127.8 MPH) increase in performance on that swap. I dyno tested two different sets of Indy M.W. intake port heads, a set of SR and a set of CNC ported 440-1, I used the same intake and carb. on both sets of those heads. The 440-1 heads made 50 HP more on the dyno but I didn't run them on that motor at the track.
The car ran a best of 9.993 at 134.6 MPH on Oregon 91 octane pump swill through the 3.0 exhaust system exiting at the rear bumper with the SR heads and a 400-3 intake and a Holley 1050 CFM # 9375 non HP carb
The right foot controls how far open the throttle blades are open, doesn't it The camshaft, intake and carb and cylinder heads determine how many CFM the motor will consume at WOT
Keep in mind though that I am a drag racer first, not a street racer or show car type of guy

This description doesn’t sound like someone targeting the 10’s.

A pump gas 505 with std port heads and a low maintenance solid flat tappet will easily make 600hp & 650ft/lbs.

My suggestion for the 270’s is really based on the possibility the OP might want to up the ante down the road, and that’ll make it easier to do should things go that way.

But as for what the original goals are.... easily achieved with std or MW heads.

1968 Dodge Charger,4050lb with me Street car, COLD AC, 512 low deck, 440 source stroker kit
9.7 compression,Morel high rpm roller lifters, Hughes hydro roller cam 255,258@.050,
.608/.613 lift with 1.6 T&D rockers with B3 geometry correction,Trend push rods, Indy 400-2 intake
that I ported to max wedge,1050AN 4150 pieced together carb,
440 source Super stealth heads max wedge size that I ported flow 330 @ .700, with Farrea valves,
Comp Beehive springs, 1 7/8 headers, full 3" magnaflow exhaust & tail pipes.
A518 overdrive trans,4000stall lock up converter, alum driveshaft,
3.54 Strange Dana 60, Caltrac bars & split mono springs with sliders.
325-50-15 MT drag radials street. drove 80 mph, 80 mile round trip to the track, dropped the air pressure in the rear tires, turned of the AC & made a easy , short shifted pass,11.33 @ 121, next pass went up against the converter 2500 & it blew the tires off, got to hot outside for me, drove home in the ac. smile

If I had it to do over I would get the Trick flow 270, even though I did my own port work I have a lot invested in these 440 source heads.

I wouldn't use the real max wedge heads, to rare. $$ to mess up.

Dwayne is correct. I'm currently not looking to get into the 10's but I do like the idea of spending money wisely and planning for the future. If I can spend some money now that would make any upgrading easier down the road I'd like to consider taking that route. Like what 383man did with his heads and build.

csk, how do you like the Morel lifters? I have not considered a hydraulic roller but I have noticed a lot of guys with great cars running them like you, therocks, GY3 and AndyF etc. I think I'll pursue the head upgrade and see how much money would be left to possibly go with a hydraulic roller setup.

An "on demand" power adder like a small shot of nitrous allows you to have a reasonably mild street engine/converter/gear combo.

Open the bottle, spray a small plate shot and dip deep into the 10's and possibly 9's.

Nitrous loves a 3.54 gear and a tight converter.

My build thread details how I installed my system and the results.

If you have a $2000 budget for heads then you can buy a set of Trick Flow 240 heads. Sell your Stealth heads for $600 or $700 and use that money to buy a hyd roller cam and lifters. You'll most likely need to add a little money to the pot for gaskets, pushrods, etc. but the damage shouldn't be too bad. The TF 240 heads on a 505 short block will make more power than you really need in '65 Coronet. Especially if you still have four wheel drum brakes!

Good luck and have fun.

I got the high rpm Morels, kinda pricey, I went hydro roller after having a solid FT failure,I have 1000 miles on it since the change, my valve train is not the quietest in the world, my cam has a fairly aggressive ramp,this car is a BLAST to drive, I just got home from a 75 mile freeway run, if I had the gas money I would do that more than a couple of times a week LOL. so far no tuning,1st easy pass 11.33 @ 121 1750 DA

What cam cam and lifters we're you running when you had a failure? Did you lose a lobe? That is a nice pass especially for a first run!

I had a Howards cam & Trend Tool steel lifters, running the hard lifters made it fracture, Flaking the nose of every lobe, That is what Dwayne suggested as the cause & I agree with him, quite a few people have had the same results that I did, I probably would have been ok if I had not used Tool steel lifters, very expensive mistake,although cam & lifter people said things would work GREAT LOL, I just did not want to take another chance on Solid FT cam again, a lot of people have NO problem with plain EDM lifters.

Very cool car, if you lived closer we could do some cruisin!

Thanks ProSport, if you ever make it down to the Houston area let me know