Thoughts on heads

[Gr8polarbear]

I currently have a 383 hydraulic flat tappet cam with 906 heads on it. Cam is the Lunati Voodoo 10230703LK. I am looking to get a new set of heads and since trick flow supposedly wont work on a 383 I am looking at Edelbrock Rpms. I cant remember if the pistons are 9 or 9.5 to 1 but the guy said they are just flat top pistons when i bought the car. I would like to get about 10 or 10.25 to 1. I am looking to run on pump gas preferably. Right now i can run 89 octane or 90 ethanol free with no problems. I have not even tried to use a lower octane. Which cc edelbrock heads would you recommend to buy? I know the 906's are supposed to be around the high 80's. I dont want to get to small of a chamber and need to used octane boost or race gas. I know that the best way to find out would be to measure how far the pistons are in the hole but i would like to buy the heads before even taking apart the engine if possible.

 

[halifaxhops]

Take a look at the 440 source heads. I am leaning towards them myself.

 

[496 polara]

440 source or the sidewinder heads have a small enough chamber to get you closer to where you want to be. 75-80cc would be the target range.

 

[PRH]

Wait til the season is over, pull a head, get some measurements, then make decisions based on real data instead of guessing.

 

[cookietruck]

The smaller chamber option would be the 75cc estreet edelbrock heads.

Or mill the 84cc chamber edelbrock copy heads.

 

[PRH]

The smaller chamber option would be the 75cc estreet edelbrock heads.

Or mill the 84cc chamber edelbrock copy heads.

.030 383, zero deck flat tops with no valve pocket, 75cc heads, 1cc crevice volume, .040 gasket……. Gets you to about 10.25cr

 

[Dart Frog]

I would do a compression test at least give you some idea of your current cylinder pressure.

 

[fishmens67]

I am looking to get a new set of heads and since trick flow supposedly wont work on a 383

Trick Flow heads certainly will work on a 383.

 

[Gr8polarbear]

Then why does trick flows website say they wont. I have read where people have changed the cylinders to make them work and i am not wanting to do that. I just want to get them checked over and bolt on. I would love to put some trick flow 240's on it.

 

[RustyRatRod]

Then why does trick flows website say they wont. I have read where people have changed the cylinders to make them work and i am not wanting to do that. I just want to get them checked over and bolt on. I would love to put some trick flow 240's on it.

Think about the stupidness of what they are saying. There's only a .070" difference in bore sizes from the 440 to the 383. That's .035" per side. If they made those heads THAT close, then they wouldn't fit the 440 either. Besides, even if the bores need "a little clearancing, what's the big deal? You're talking about spending big bucks on heads and you're gonna let "a little" machine work stop you? That's ridiculous. Besides, They'll fit.

 

[fishmens67]

Jim tested the trick flow on a 383 at lifts into the .700 range, no need to clearance cylinders.

 

[fishmens67]

I have read where people have changed the cylinders to make them work

Well they are wrong

 

[Gr8polarbear]

Think about the stupidness of what they are saying. There's only a .070" difference in bore sizes from the 440 to the 383. That's .035" per side. If they made those heads THAT close, then they wouldn't fit the 440 either. Besides, even if the bores need "a little clearancing, what's the big deal? You're talking about spending big bucks on heads and you're gonna let "a little" machine work stop you? That's ridiculous. Besides, They'll fit.

Right now i am just looking for a set of heads to slap onto the engine that is in the car now. My plan is to stroke a 400 and swap the engine down the road anyway. I would love to have trick flows that way i can just transfer them to the stroker instead of buying another set of heads. But I am not looking to have a lot of machine work (but dont sound like it is necessary) on the current engine. And if i am going to pull the engine to have the bores clearance i might as well wait till i am done with the stroker which could be a year or two.

 

[Car Nut]

Jim tested the trick flow on a 383 at lifts into the .700 range, no need to clearance cylinders.

Was it a stock 383?

 

[Gr8polarbear]

The main reason i am wanting to change the heads on this engine is because once it hits 5200 it falls on its face. I think the springs are getting a bit lazy. The cam that is in it should pull to 6 or a bit above. I dont know if the intake has anything to do with it or not, i would not think so, it is a weiand dual quad set up. I can only find limited info on the intake but says it is good into the mid 6000 range.

 

[mygasser]

as above run it 'til the winter then pull the heads to check exactly what you have before choosing. in the mean time it's easy to swap valve springs with the heads in situ so i'd do that for now. as above also the trickflow heads have been tested on a 383 and they do clear the cylinders so it seems a no brainer. especially as they'll swap onto the proposed stroker 400 later on.
neil.

 

[fishmens67]

Was it a stock 383?

Yes 4.25 bore

 

[PRH]

While I realize looks can sometimes be deceiving, that intake doesn’t “look” the part of something that will be strong to 6000+rpm.
I also think when bolted to a set of TF240’s, it will knock off a bunch of flow.

I’m not suggesting you don’t use it, I’m just making observations.

 

[Gr8polarbear]

While I realize looks can sometimes be deceiving, that intake doesn’t “look” the part of something that will be strong to 6000+rpm.
I also think when bolted to a set of TF240’s, it will knock off a bunch of flow.

I’m not suggesting you don’t use it, I’m just making observations.

I would have thought the shorter runners would be fine for higher rpms. If i go to trick flows i would be putting on a performer rpm with a single carb. Unless you can recommend something better for mainly street and some strip.

 

[Ricks70Duster340]

I would have thought the shorter runners would be fine for higher rpms. If i go to trick flows i would be putting on a performer rpm with a single carb. Unless you can recommend something better for mainly street and some strip.

The Performer RPM will do nicely for street use. I use the Performer 440 with a Quickfuel 750 VS and it has excellent street manners and pulls strong when I get on it.

 

[PRH]

I would have thought the shorter runners would be fine for higher rpms. If i go to trick flows i would be putting on a performer rpm with a single carb. Unless you can recommend something better for mainly street and some strip.

Fortunately, intakes are easy to change, so if you feel like you’re leaving something on the table power-wise, it’s simple enough to try something else.

I don’t know how mild/wild a combo you plan to build, but I guess I’d put it this way……
With TF heads on a stroker and a HP target of about 550hp and up, the RPM will be a bit of a cork.
However, it would still retain its excellent street manners.

 

[JDMopar]

@PRH If the Performer RPM will leave flow on the table, what would be better for a low deck stroker, say 470? Victor? Trick flow intake? Still for a street car.

 

[496 polara]

M1 single plane or a street dominator .Play with carb spacers for fine tuning. Performer rpm will make plenty of torque and hang on higher than you might hink. Have an rpm intake ported.

 

[Bewy]

That intake looks like it is a factory marine intake....or Offenhauser. There is a reason many people are not using Offy intakes.....
Your 906 heads should be able to feed a 383. I would first check v/springs & then get a better, single carb modern intake such as the RPM.
Also, the header pipes look to be a large diam for a 383.

 

[kbr577]

@PRH If the Performer RPM will leave flow on the table, what would be better for a low deck stroker, say 470? Victor? Trick flow intake? Still for a street car.

The Trick Flow intake for the heads.