528 hemi 620Hp looking for 750hp need advice

Hi,

I have a 1966 Dodge Charger ( 4,000 pounds ) with a 426 hemi bored and stroked to 528CI. The heads are stock 66 559 casting iron with slight polish. I am running the stock dual plane 2x4 intake with a pair of new style carter 625cfm carbs. The Cam is 267@50 duration and 617/587 lift. solid lifters flat tappet. 10.5 to 1 compression on 93 octane no issues
3000 stall converter and cheetah manual valve body 373 rear. TTI 3 inch exhaust and TTi headers.

The motor dynoed at 620Hpat 6,000 rpm 630 lbs torque at 4100rpm and fell off from there. Over 600 lb toque from 3000 to 5200rpm and 542lb torque at 6,000rpms

90 percent street driven.


My question is do I need to go to a single plane intake? Change my heads or port them? I would like to try to get 750HP and still keep the torque.
I am thinking that all the low end torque is wasted as I am over 3000 with the converter anyhow? Am i missing something?

Thanks for the help  

I don't know but 1050 cfm & single plane would be good along with some porting and
11.1-11.5 comp would help a lot especially if you find the cam is the limiting factor.  
age is no lock on brillance

This is a question I hear a lot, I need more power. Can I ask why you need 750 horsepower to do 90-percent of your driving on the street? I would think that 620 would be plenty.

Anyway, you'll have to tear the engine down to make some serious changes if you want to add 130 horsepower, a simple head and intake swap ain't going to do it.  
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Some people are like Slinkys; they're not very useful, but fun to watch when pushed down the stairs.

Thanks 340spdvaliant, I think that is the direction I am going. New fully ported stageV heads and propbaby the Stage V 2x4 single plane intake.

RBolig...Well as humans we always look for more.    I've owned this car 9 years and got very used to the power. I can honestly tell you maybe 130Hp will be over the top but at 620hp at the motor I can definitely use abit more. I am not going crazy like putting on a blower and looking for 900 to 1000HP which I think is mostly unusable.  The 66 charger is heavy but the sustpension and wheelbase helps to hook up nicely on the street. Dont get me wrong, I can always fry the tires off it.

Alittle more info
The block is a MP simease block and the motor was built by Ray Barton. It has newer style Rods and Rockers and new hardware. It is built pretty tight for what it is.  

Not a problem, I just get that question a lot, and thought I would ask. Anyway, I too build more than I need sometimes. We just got done building a 500 Wedge with 720 horsepower--don't ask me why.  
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Some people are like Slinkys; they're not very useful, but fun to watch when pushed down the stairs.

Why?
Why not 720hp, if you can build it then it sounds good to me!

Hey randy have you guy's built a 472 or thrown a 3.90 offset journal crank into a 400?
And what do you think, and compare rpm wise with the bigger strokers?

I ask cause thats the next stroker I am building for myself [right now], see I'm on this path of building all the engines I can and just have them on the stands ready for action when I get too used to the power that currently resides under the hood.

So far I have built and stored
227 10.1 ported head 6 old MP.490lift solid cam
318 steel crank ported '234' head 9.1 340 cam [possibly sold]
344 10.5-10.8 ported x heads .533 w/1.6
344 12.5 diamonds  ported j heads MP .557[unassembled]
410 stroker 9.8 full ported j heads Engle .575 solid
440 spd pro 10.1 mild ported 906 heads engle .534 hyd [just sold, too mild for me]  
age is no lock on brillance

528Hemi - contact Tim at For Hemis Only.  He'll provide you with a kit of parts that will pump up the power to whatever level you want.  The Stage V heads and intake should do the trick that is for sure but Tim might have other ideas as well.  Don't forget that Mopar Performance has some new Hemi heads out that work really well.  They are aluminum so that would also save a bunch of weight off the front of your car.  

I built a 528 ci hemi. Havent started it yet. I wanted 800 + hp but streetable.  I went with a low compression engine 8:1 and put an 8.71 bds supercharger on it. I can run pump gas and a mild cam and still make tons of torque and hp by just changing pulleys. Check my car out in readers rides. Search on koister or go to this link
http://rides.moparmusclemagazine.com/ride/1017030/koister/1970/dodge/challenger/index.html leave a comment if you take a look at it.

I have pictures of the engine there as well. I can provide you with all of the specs if interested in pursuing this approach.