Joe, if you are also pushing the position that the same set of heads is the BEST POSSIBLE choice for a 350 horse engine and a 500 horse engine then you are misguided too. I'd guess that the reason so many "jokers" on here hand out the same prescription for build goals so different is because most people asking build questions are building their first or second engine and don't really know what they want. After running a while maybe a lot of them wind up wanting "more" and upgrade the cam so the bigger heads were actually used.
And Joe, since you think I've asked a noob question maybe you have some personal experience and/or dyno results you can share on a mild 383 using stock valve sizes vs. larger valves? I don't mean repeating what you've read or heard like a parrot, I mean actual first hand experience. If you can't then you're pretty far off base calling someone inexperienced or a noob because they didn't know any more than you did in one area. Or maybe you should add noob and inexperienced to your signature so people will know where you're coming from.
The consummate noob approach would be to listen to what some of the racerboys repeat like trained parrots when pushing their cookie cutter "cool builds". Then you wouldn't be afflicted with the task of thinking for yourself or researching or asking questions and you could just go with not only larger valves but heads and cam too. Just like the 450 rwhp guys use when the noob really wanted a stout and very responsive daily driver with around 350 rwhp. Of course a noob would probably be scared to post about such an uncool goal as massive midrange and only 350 rwhp because somebody might think he was not manly.
I firmly believe that for people building cars that see a good deal of street action and who actually have a firm idea of what their long term satisfaction level is on HP that going BIG is not usually the best approach. I see a good bit of lip service to a "matched package" of heads/cam, exhaust, compression but it looks like what most people actually mean is go with matching stuff that is the biggest, baddest stuff you can tolerate. Smaller ports deliver a disproportionate improvement in part throttle torque and throttle response. You know, the stuff that makes a daily driver feel really fun and impressive if you're not WOT. Thinking ONLY in terms of peak HP numbers at WOT when gauging a motors effectiveness and enjoyment level works fine for a track only car but completely ignores the bulk of operation when operated on city streets and highways. If you have a moderate HP goal then building to hit your HP goal with the mildest stuff that gets you there makes for a more enjoyable ride that is more responsive.
Now flame away but make sure you read the last three sentences and address them, otherwise it's just bantering without any real debate.

 

Ever THOUGHT that the same formula is repeated 'cause people KNOW what they are talking about and have done more than ONE engine to back the receipt up.
They probably have gone SMALL and found that don't get it.
When the SAME receipt is repeated like a PARROT there must be SOMETHING to it 'cause if was wrong, then people would say so.

Ya gonna be lucky if yours even runs.

I have customers with a 250*@50 cam and 300CFM heads using their car as a DD and run in the 6's at the local 1/8 mile on motor.So when ya get through butchering your heads and building your torque monster please let us know how well it didn't run.

Again I ask for ya to post any relevant info to the "receipt" being wrong. NOT YOUR OPINION but Data from any source.

 

Lots of good advice, I think right now I have to agree with Sam Pace on this one. A combonation of people's advice should be considered. To keep this going in a HELPFUL direction, for me and anyone searching on the same topic, lets do this:

I have a CC306 cam. If I go with a 383 and this 'mild' cam, what kind of heads should I be looking at? Not sure if 400RWHP is doable from this cam, but I'm sure 350RWHP and 400 FWHP are possible. I'm thinking that I'd have the torque-fun of a 383 with the reliability and DRIVEABILITY of a smooth riding, solid cam. Then I'd have power on the highway when I needed it and the red light acceleration to burn a few ricers to the ground (like I can't do that already ) Remember, this will be a DD, and I commute 45+ miles one way everyday. I don't want a huge lope, but I do want some fun.

 

If ya got a built 383 and DON'T make 400 RWHP there is something radically wrong with it.
The bigger the heads the smaller the cam can be for the same HP level.
Ya also have to consider the intake tract and the % it takes OFF the head flow. Ya need to match things.

 

?????? That last sentence needs to be in english. From it I got this:

I need to be aware of the intake side of the cam so it matches the amount of flow the heads will produce. Is that right? So if I had a 306 cam, what kind of heads would I be looking at? LE2 flow numbers?

 

The bigger the heads the smaller the cam has to be to produce the same amount of HP

The stock intake will loose 12% of the flow even when ported. That alone knocks a 300CFM head down to 264.
Then ya have the 6" K&N filter on it which flows about 750CFM and ya take the flow the pistons see down some more and if the CAI isn't right or the TB is to small,down again. So ya may wind up with 245/250 from your set of 300CFM heads.
With GOOD flowing heads/intake system ya don't need as much duration or lift to make the HP. The flow is filling the cyl due to port flow not holding the valve open
longer and ya don't need to lift the valve as high to fill the cyl.Lift is good to get the valve out of the curtain area. I like lift.
Unless ya get air into the cyl to put more fuel with it to make a bigger pop, the HP won't go up.Ya can put a BIG,STUPID cam in it and sorta make up for the heads,but there are limits to that.

The larger the flow through the intake system the more HP ya can make.

 

The cam you mentioned is a mid to upper range cam.
I think you might might wanna find a cam with less duration and a little more lift. Don't be afraid to be little conservative in this area
You said you drive 45 miles one way.
Are you planning to use 1.6 rockers?
Heads, you want to look at LE2 numbers. Don't forget this is a small-big block you are building. Intake you def. wanna open up the runners to match the heads.
What size throttle body and injectors are you planning to use?
If this is a Hwy cruiser why would you switch to an auto?
A well thought out 383 will be around 400 -440 at the crank and will be a SMOOTH DD.

 

.....Nah there's nothing to flame......your just seem to be off in your own world when it comes to what you think does what with changes to fuel injected engines........according to your hair brain logic, Which I guess comes from building 3 "basic as could be" engines in the past, even the car in my sig here on this site should be really mismatched for it's purpose, being WAY down on off idle torque as well as drivability.....but to the contrary, the below car is a 70mile a day daily driver.....With EVERY mod you see listed below, it was driven for several months (5 to be exact) "even" with the stock 2:59 gears, and a bone stock converter, and the drivability and low RPM torque, was actually as good as it was stock (which was gobbs of torque right from idle)....DO YOU EVEN UNDERSTAND WHY?...NOPE......This setup in my sig was designed to have pretty good flowing heads(290ish on a 3rd party bench) while still having really good low and mid lift numbers as well , about the same compression as stock, and a fairly small mid 220's @ 50 cam, that (if I decided to later on) I could add more cam and still gain from it since the heads could support it with no problems, and it worked out great for it's intended purpose which is an everyday steeet car with a "once in a while" track visit.......(as a hobby)Iv'e been building engines from the ground up for over 17 years as well as owning several fully "self built" mid 9 and 10 second cars(some NA, and some with some seriously advanced nitrous kits).....and a whole bunch of everything inbetween........like I said in the begining, you just don't really understand what does what, and with almost no experience it's easy to see why

 

 

You made some interesting points Joe but the way you used your massive experience and my supposed lack of experience to sell your side doesn't really seem totally accurate. I said I'd built 3 383's, not a grand total of 3 engines If the stuff you have done is all it takes to credit or discredit someone then I'm set. I've done one off engine conversions like a crate Viper engine into a truck, LT1's into vintage Jags and all sorts of older stuff, fabbed sheetmetal intakes for fuel injection conversions and then installed and tuned aftermarket EFI to run it, big block and small block street and race engines, bunches of nitrous, turbos, superchargers, and lots of dyno and road tuning mixed in for good measure on engines as complex as a pair of in house built 1000+ horsepower dual whipple supercharged EFI big blocks which were used in a Fountain 33 ft. cigar hull that clocked 113 mph. Once converted a Ferrari 308 from Bosch EFI to Electromotive, changed a clutch in a Lamborghini Diabolo, setup a couple of Vipers for road racing. Rebuilt my first automobile engine, a Rocket 350 in my '72 cutlass in about 1988. I did my first tuned port engine conversion into a '69 Camaro in 1990 and built my own harness. Perhaps the most impressive project I've done is an electric supercharger install onto a 1.0 liter three cylinder Geo Metro, front wheel horsepower jumped from 30 to 33 or something like that. I'm also an ASE certified mechanic and Microsoft Certified Systems Engineer. I guess that's enough of laying out credentials to prove you know more than someone else. Credentials don't mean you've worked with both sides of a debated topic or have any objectivity.
Just because it's not popular any more doesn't mean that for a good number of people a aftermarket TPI setup and/or conservative cam/porting would be much more fun. Torque and throttle response at small throttle openings ( meaning strong, instant power that is right there when you touch the gas) is what makes a stout street car fun to drive much more of the time than stong top end. For me at least. You can throw out the same dyno charts that everyone has seen which still say that big cams and agressive heads make mucho topend horsepower. What do you really know about how this setup affects torque production under high manifold vacuum conditions and part throttle snap?


I have built a bunch of big bore bike conversions on two and four strokes where a 10 to 15 percent increase in displacement with minimal port or cam changes made a much greater than 15 percent increase in low/mid throttle response and part throttle power. The difference can be spooky. I've noticed the same pattern in a number of automotive engines where the displacement was increased. From my particular perspective an engine that feels like a well tuned big block in the midrange is the most fun on the street. If someone has a firm HP goal and can stay toward the conservative side of the sprectrum with the cam, porting, exhaust and induction they use it is possible to add a good deal of fun value for street driving.

I don't have a problem with people overbuilding stuff so much as not considering or even being exposed to the fact that there are significant tradeoffs involved which might decrease the fun factor much of the time. The tradeoffs don't show up so much on a WOT dyno pull. The major losses are at smaller throttle openings. If your approach is to build the most HP you can live with on the street then snap and low/mid torque aren't primary considerations. If you have a moderate HP target then a system approach on the conservative side can reach your goal and crank the fun up. Does anybody remember how weak the LT1's felt on throttle response or midrange compared to the TPI's? That's the kind of power that you can tune for if you want a car that is impressive and fun all the way around. A good many people don't realize how much they would giggle around town with this type of power.

 

So.... you are trying get a rise from everybody.
Then slam everybody w/expert advise on stuff.
I am going to ask again who are you? Why are you being such an ***!
Why do you ask such simple questions? Then blind side and bash people with stuff you already know the answers to? I guess your sig fits you to a "T"
Why do this when there are better ways of explaining your point of view?
Oh, well I guess you can't explain certain things.
Good luck on your build I hope it turns out well.
I would like to see how your car performs!
Sorry to rant and hijack this thread.

-Sam

 

 

go 355 u can always go 383 later... no more boring or anything required.. just use the .030 383 kits they sell.. about $1,000 more when u want to step up and u get around 90-100hp and tq

 

i did a 355 to save money, but let me tell you, a 355 done correctly is more expensive than a 383 with cheap ****. Do what you can afford with the correct and good quality parts.
-Jason
Good Luck

 

You won't gain 100hp.