cylinder head question?/AGAIN

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dustya_383

dustya_383

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So Today i looked up the casting numbers on my heads that i took off the 383 i bought a while ago and found out they are from a 68 440?? the number was 2951250 they had a 2 brrl intake mounted to them so my question are these a good set of heads to do work on and get a good amount of power out of them or should i get some 906's or 452's??? thanks
 
Hi guys, my sources tell me :read2:#250 heads are early 68 383 only heads.
I found some when I was chasing #906's, I cc'd n benched em. same 86cc chamber as a #906 same port as a#346. so not a bad head, if you already own em, it could work out very cost effective.
 
When I looked up that casting number on mymopar.com it told me that they were 68 440??? What source did you use
 
whats your performance goal?

i wouldnt dump a bunch of $ into old iron heads when you can get aluminum 440source Stealths or Edelbrock Rpm's
 
My goal is to get around between 450 and 550hp. But for the street not track although it would see the track a little. For a few runs to see what kind of numbers I could put up
 
dustya_383 said:
My goal is to get around between 450 and 550hp. But for the street not track although it would see the track a little. For a few runs to see what kind of numbers I could put up
Click to expand...

Sounds like you're on a tight budget, If the heads you have definitely have 2.08" I and 1.74".E, spend a bit of money to have them cleaned up (surfaced, bowl work, gasket matched, etc). It shouldn't cost more than about $400, IF some parts can be re-used.
 
I have a dozen or so old soft cover books, some not so old plus there are lots of sites.
450 to 550 is a big step for a 383, I would go with your #250's for 450hp and eddy rpm's for 550hp.
Check out the mopar muscle web site they did a 450hp 383, it was very basic unported heads, 10.2 comp, 557 cam, mi and headers, enjoy
 
timopar said:
450 to 550 is a big step for a 383, I would go with your #250's for 450hp and eddy rpm's for 550hp.
Check out the mopar muscle web site they did a 450hp 383, it was very basic unported heads, 10.2 comp, 557 cam, mi and headers, enjoy
Click to expand...

Good point. The OE heads can do OK on the street and the 450 HP target isn't hard to get or do. Even with the OE valves, basic porting and back cutting will get ya there for less than the new aluminum heads.
 
timopar said:
I have a dozen or so old soft cover books, some not so old plus there are lots of sites.
450 to 550 is a big step for a 383, I would go with your #250's for 450hp and eddy rpm's for 550hp.
Check out the mopar muscle web site they did a 450hp 383, it was very basic unported heads, 10.2 comp, 557 cam, mi and headers, enjoy
Click to expand...

I love how everyone uses that article to show what a 383 can do , the problem is the HP claims are BOGUS , the dyno used was known to give inflated numbers and eventually they admitted their correction factors were the cause .
 
I can get a set of ported 452s I forgot wat valves but have been worked on quite a bit. I'm guessing this would be the better route to go rather than mess with. And waste money on the 250s right?? I hear it all the time its easy to get a mopar to go fast . . 450 to 550 is reasonable yea???especially out of a big block
 
Well, yea, it is easy, to a degree. Lets not just throw parts at something and expect magical numbers to pop up. Your also listing a 100 HP difference. That's nothing to toss around like a HP gain from a dirty to clean air filter.

I don't know about the 250 head. I'm also not sure exactly what it is your looking to do...exactly. Given the engine size (Via bore and stroke) it should be easy to get 400 HP with basic good rebuild work and a set of higher compresion slugs. Unless your current ones fit the bill.

Now these ported heads. Valve size is important along with what exactly they did for the porting work. If you find these heads with a full port job and gasket match along with bigger valves all around, they won't work to well with a Hwy. or modest gear ratio and/or a small cam.
 
JohnRR said:
I love how everyone uses that article to show what a 383 can do , the problem is the HP claims are BOGUS , the dyno used was known to give inflated numbers and eventually they admitted their correction factors were the cause .
Click to expand...

This reminds me of a posting earlier about what is a happy dyno, what makes it happy?

Well, at least there printing corrections.

Also, often, the write ups have a base pull and a after parts added pull so you can see a difference. Since there (The rags) are the only ones out there doing anything like this, what else does anyone have to go on?

Have you a build up like theres? Can you do a article? With pictures?

Hell, I'd love to see it and I'm sure the OE poster would as well. I have a 400 on deck to do! Whatcha got John?
 
I'm not saying I want to go from 450 hp to 550 hp wat I meant was thast the hp range I want to get into after motor is finished I have nothing now but a bare block and crank, I'm going to get my block bored and honed decked haave everything balaced and all. Now I just need to know how to choose a cam , camshafts are foreign to me when it comes to duration lift and centerline and all that.I also want to know will my stock con-rods hold up to that amount of power or will I have to purchase stronger ones??
 
Well, that's a big range and the message I was trying to get across. BUT, your questions...

Now I just need to know how to choose a cam , camshafts are foreign to me when it comes to duration lift and centerline and all that.I also want to know will my stock con-rods hold up to that amount of power or will I have to purchase stronger ones??
Click to expand...

On the con rods. The OE units can handle the HP. BUT If they require resizeing, striaghtening , balanceing, well, the cost of doing so can add up very quickly and end up more than new rods. The OE rods strength is not in question at these levels, correcting any issues with them is and at the cost it'll take.

On a cam, this is a street engine?

This subject can get tricky and it will certainly have alot of opinions.
Lets get some basics out of the way. Answer this list to help zero us all in on a decent selection.

We all know it's a big block 383 Duster.

Trans type?
Gear ratio?
Tire size?
Intake manifold to be used?
Would a stall converter change be OK for you?
What is the overall goal of the car. Not in terms of HP, but as a;
Daily driver, street strip or just strip car?
Is idle quality important?
Lastly, what type of cam is the one you want to run? A Hyd., Solid, Hyd roller or solid roller?

Hyd. cams are easiest to drive and live with and require zero maintanice. (SP?)
 
Trans is a 4spd
Gears I was thinkin 3:55 or 3:73 sure grip its a one legger now with 2:76 or 2:93??? A highway gear is in it right now
Tires are 28 inches?? 275 60 15
Air gap intake
Want it to be a street car but want to hit the track everyonce in a while
I want a "lopey" idle
And a hyd. Cam
 
dustya_383 said:
Trans is a 4spd
Gears I was thinkin 3:55 or 3:73 sure grip its a one legger now with 2:76 or 2:93??? A highway gear is in it right now
Tires are 28 inches?? 275 60 15
Air gap intake
Want it to be a street car but want to hit the track everyonce in a while
I want a "lopey" idle
And a hyd. Cam
Click to expand...

Sorry Dustya but Air Gap is an intake name for Small blocks, if it's an Edelbrock it should be cast in like Performer RPM or Torker.
 
All big block intakes are of a air gap design.
An interesting choice IMO. It'll provide the sound and power range your looking for; http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=717&sb=1 2-6 grand rpm
It's a split duration to help the heads/engine breath better.

Or this one designed to idle ruffly;
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=1497&sb=1 2200 - 6100 rpm.
(Not a fan of the thumper series myself. It's centerline and intake opening points are moved downwards to chop heavy. It's a few hundred RPM's higher in the power band. The exhaust valve is held open longer.)
 
I'm kind of partial to the Lunati Voodoo line. The #60303 might work good for you.

Ted
 
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