I posted this over on forabodiesonly but thought i would give it a shot here too... I'm just about ready to make a head purchase for my new 512... I've been leaning in the direction of the 240 Trick Flow but now stuck between the 270 TrickFlow or Indy EZ-1.... Opinion? or a entirely different direction? Im open to all options.
I want to be in that 750ish range and low ten ET

I'm putting a set of 440-1 Indy heads on mine that I ported. Getting some real nice numbers already but I may go ahead and upgrade them to a 2.250 valve since I have them sitting here.

The engine would need to be fairly well sorted out to make 750 hp with the 240 heads. It can be done and it would be a screamer but you would need to have your act together to make it happen. Cam, carb, intake, etc all need to be correct.

How much compression are you willing to run? If you are willing to run race gas then building the engine at 13:1 makes it a lot easier to make the power number. You can do it with pump gas but the combo would need to be super well dialed in.

A 512 can definately use the larger MW port window. what will the motor be used in, and for? Trans type? Pump gas or race? Budget?

Low deck build?

Body style?

I prefer the raised exhaust port heads when they can be used.

As mentioned previously, cr you're planning on?

Race only or street strip?

I'm fine with race gas... the car will be 80% track and 10% street so I am fine with a higher compression. (and when I say street probably 10mile round trips or so. Nothing major)

71 demon. Mostly a steel and glass car with the exception of hood and trunk lid. I'm guessing somewhere in the 2900# range
as far as trans Ill probably end up going with a new TCI
Race Gas
Budget: Maybe 2,500 to 3,000 on heads

Ok so now we have a rough weight of say 3200lbs at the line and assuming a good chassis under it a 750hp TF270 headed motor should run 9.40's or thereabouts. If thats where you wanna be further down the road, then fine, build that with a big roller and 12:1+.

However if all you wanna do is run low 10's and stop there and not have to have all the extra Tech stuff, that can be done with a mild 10>10.5:1 620hp 512 that will run 10.0's with just a solid cam and probably with either of the heads you mention above.

You need to think about the headers since there are low deck and RB engines then there are standard port location and raised port. So if you are going to run an off the shelf header you might want to sort that out first. If this is a low deck engine then perhaps you'll want to go with a SR head and use a TTi header.

A low deck 512 with 13:1 compression and TTi headers should make 750 to 800 hp with a set of ported SR heads. Low deck intake choices are slim so that is a downside.

All true....... However, many(most?) people don't seem to get 100% of the potential performance out of their motors, and it can be time consuming and costly to figure out what the problem is.
On the other hand, if you're starting from scratch, it's not really that much more money at all to build a 700-725hp motor than it is a 625hp one, and then the "car" doesn't have to be as good for you to be able to achieve your goals.

TTi makes headers that would work for either a B or RB build, for either std or raised ex port heads...... So that part is easy.
EZ-1, EZ295, SR295, TF270....... They will all get the job done.

Flat tops and 75cc heads puts you in the 11.5cr range, which should be plenty.

440-1 heads would be my choice, we use them a lot and work real well for all types of builds. The dyno sheet posted is a 540 we did on pump gas, solid cam, 4150 carb, just a little bowl blend and the valve job, no porting and the intake was just cut to fit. Yes its in a street car also.

Howdy Pete, that's an awesome combo...great work!

How big was the intake valve and who's rocker setup/ratio did you use for this?

Does this setup need ported pistons and vacuum pump too?

Thanks!

My old pump gas 1971 Duster weighed 3450 lbs. with me in it(260 lbs.+), radio, heater, full interior with a chrome moly 6 point roll bar and no back seat, fiberglass front bumper and lift off race weight hood.
Hedman 2.0 x 3.5 fender well headers and a full three inch exhaust to the rear bumper.
The motor was a 400 block 4.375 bore with a 4.300 stroke crankshaft for 517 C.I., 10.78 to 1 compression ratio, Indy SR heads with M.W. size intake ports with 2.19 intake valves and 1.81 exhaust valves, Indy 400-3 intake and a Holley 1050 CFM #9375 Dominator stock carb. Harland Sharp 1.6 ratio rocker arm kit, Comp Cams custom solid roller cam that was 260 degrees @ .050 intake with .420 lobe lift, 266 @ .050 on the exhaust with .409 lobe lift ground on a 108 LSA installed at 106 intake lobe center. That motor made 727 corrected HP at 7000 RPM in Klamath Falls, OR which is at 4300 FT. I swapped the heads and rockers to a set of CNC ported Indy 440-1 with the exact same compression ratio, same cam and intake and carb. and that combination made 775 HP at 7000 RPM also on Oregon pump swill also
Ladder bar rear suspension with Strange Engr. double adjustable coil overs and a diagonal link Dana 60 truck housing cut down with Strange Engr. 35 spline axles and spool, stock Dana 4.10 truck gears, 10 inch wide rear wheels and 315x60x15 M/T ET Street Radials, 10.00 ET at 134. + MPH corked up a bunch of times on Oregon 91 octane non ethanol pump swill with the air cleaner on
I had a set of CNC ported Eddy RPM heads and a low deck Eddy six pack intake and a set of stock type Holley 440 6 pack carbs. on the car before swapping to the indy heads and intake. The six pack combination ran low 10.30s at 127.+ MPH corked up a bunch of times also
IHTHs

The heads are the base 440-1 with 2.19 intake valves, we used T&D single shaft rockers with 1.6 ratio, valve lift is .620, 1/16 rings no gas ports and no vacuum pump. Its hard to better that cylinder head for engines like this. We have made over 900 HP in race from with our bracket roller cam and compression.

Thanks for the details, very much appreciated...

We have been doing ok with the EZ1 heads on our 512RB.....Got me a 400/512 in the works with a light weight crank! Been 9.7's with the old pump gas combo with a 4150 carb....

Your 512 RB runs great!

Will you be doing a build thread for the low deck motor?

Current thoughts for heads going on this?

Another way to look at it is a small port head on a 383 or 400 is about the same port opening area per cubic inch as a 440-1 head on a 500 cube motor,,,,,,,,,,,

Pete care to share a little on that 900 hp race motor if you don't mind..getting money right now for 1 of the musle motors blocks..you guys prefer Rb or b block sorry for him jack

That would be a RB due to the 572 Cubes. 440-1 Heads CNC ported by Indy 345 version, 440-3x intake, 15 to 1 compression, our bracket series cam 283 intake duration, wet sump, vac pump, T&D single shafts and a 2.125 carb. Pretty straight forward engine.