Rebuilding a 67 383 motor to put in front of 4-speed trans

[Sly]

Hello, i will soon be in a process of rebuilding the 383 motor in my Challenger, i will convert my car to a 4-speed at the same time.
Motor is a 67 383 with stock 906 heads, it currently has high perf stock exhaust manifolds and Offenhauser Dual Port intake. The car has a 3.55 rear end.
I would like to rebuild it to "a bit better" than stock specs, and more suitable to the 4 speed. I would like to keep the stock heads and exhaust manifolds but I thought about a different camshaft and single plane intake.
All the people having experience with beefing up a 383 for a four speed car are welcome 

[HUSTLESTUFF]

It's not going to do much good behind the 4 speed.

If you're going to put one in front, the cam selection is an area to wake it up.  Single plane good too, but don't over carb it.  I'd talk to they guy at FBO for cam choice.  Mike

[Sly]

Just corrected that 

Who is the guy @ FBO ?

[1 Wild R/T]

Building horsepower & torque with a 383 can be tough, the wrong cam will kill it... The biggest issue building cylinder pressure  when you have such a short stroke... 906 heads have 90 cc chambers which means getting a compression ratio higher than about 7.5-1 requires a domed piston...   Truly the best thing you can do is lose the 906 heads.... Get a set of 915 or 516 closed chamber heads..Now you can get 9.3-1 pretty easily.... With a little cylinder pressure the Crower 271HDP is a great cam for a 383, it features  222/234@.050 .486/.496 lift 112 centers......

FWIW 915's are hard to find & can be $$ but they get you compression without sacrificing any flow..  516" are much more common & can flow plenty for a 383.. The compression will help allot more than the flow will hurt....

[Cuda Cody]

IMO the cam is the biggest and most important part of an engine build.  It's the heart beat of the motor and will affect everything from how easy the engine is to start and how she drives.  I could not be any happier with the Mr. Six Pack Cams that Bob makes.      I've used them more times then I can count (at least 7 or 8 of them) and they always start easy and make a ton of power.... and all on pump gas!  I build to about 9.3 to 1 compression with iron stock heads.  I've done some 383's and they will make good power.  Here's how easy his cams start (this is a 340):

[video]https://forum.e-bodies.org/gallerypics/videos/1_01_04_17_12_12_06.mp4[/video]

[Sly]

Thanks for your replies, sounds interesting. The fact is I am not 100% sure my heads are 906, what heads came with 1967 383s from factory ? How do I identify them ?
Where do i find those Mr Six Pack cams Cody ?

[1 Wild R/T]

If it's original you probably have 516's....   The Mr Sixpack cam is always a  good choice, mild, docile but makes good power....


Cyl head info... The casting numbers are in the same area whether its a 906, 915 or a 516...  http://www.hotrod.com/articles/mopar-big-block-915-heads/

[Cuda Cody]

I've used the 906 heads and they are fine, but like stated above the 915 or 516 would be a better choice.  Or you can do some 440 Source stealth heads.  I've not used them myself, but people seem to like them and they look stockish.

Bob does not advertise so you have to contact him directly.  You can tell him you are part of the E-Bodies.org site and that you know me.  He'll take good care of you. 

mr6pk@hotmail.com
Bob Karakashian
248-477-7776 days
248-489-4076 eves

[1 Wild R/T]

Cody, you should try a set of 915's some time.... You might decide the 906's aren't all that... On a 440 they are ok but the short stroke of a 383 creates a problem with the large combustion chamber volume...  And the open chambers make building quench difficult & expensive...

[HUSTLESTUFF]

FBO is at    http://www.4secondsflat.com/

I like the Racer Brown Cams. 

[Sly]

What about the intake manifold ?

[Chryco Psycho]

I agree 100 % with @cuda cody
the cam s the key component in any build , I have been using the Lunati VooDoo series cams & they work extremely well also
You need to watch the RPM powerband of all the components used so a milder cam with a good dual plane intake such as the RPM may suit your needs best depending where you want the powrband to be for the use you intend

[Sly]

I think I may like better a "top end power" motor with the 4 speed and 3.55 gears too, but not too extreme though. Something that awakes around 3000 rpm up to 6000 would be cool.

The Weiand Xcelerator intake looks good and seems to fit under a rallye hood without any problem, I will search for a mild cam that suit fine.
Would you advise to keep a dual plane intake or go for the single plane route instead ?

[Chryco Psycho]

Dual plane is more low rpm friendly typically but in the rpm range you are looking at either will work but I would look more at a single plane ,some are still a lot better than others are .
Lunati voodoo 703 can should work well

[Sly]

Yes, and what intake to choose with the Lunati cam ? It will need to fit under the stock rallye hood with the stock dual snorkel 383 air cleaner box.