Looking for ( or At) Gen 1 SBC 175-185 cc heads for a mild 350

[bigmike]

Looking for ( or At) Gen 1 SBC 175-185 cc heads for a mild 350 under 6200 RPM that would come as a package with some decent quality valves and springs for a retro fit HYD roller. Any suggestions from the experts here. It seems like the 195cc - 200cc that are so common would be bigger ports than I need for this project. I would be happy with 390 - 415 HP out of this if that helps.

[ZEOHSIX]

I have a pair of new in the box phase6 Chevy Bow tie aluminum heads....they are pretty small....$675/pr I can provide REV valves too......

[user-17438]

Pretty much any stock or aftermarket head will make the hp you are looking for. maybe post a little more information about what you plan to do with the setup, do you want max torque, nice clean idle.. etc

TBI heads can make that hp goal. are you hoping or more than 400hp, but will settle for less? whats your desird compression ratio or gas requirements. single 4bbl or 2bbl, efi.etc

Edelbrock makes topend kits that will make that power and are easy to assemble and reliable

[Orr89rocz]

Afr 180 are nice. Dart shp 180 are nice and cheaper

[DaveMcLain]

Take a look at some of the heads that EQ offers. They have a head that's like a Vortec head on the inside yet has the regular Chevrolet intake manifold and valve cover bolt patterns. They can run very well and I think they offer some versions "loaded".

[user-612937456]

If you use a set of vortecs or fuelies with 2.02/1.60 valves. It is your easiest path to make your goal but at a lower 5700 rpm, you will need 10.1 compression to get 16" of idle vacuum for a milder sounding idle. If you look at other castings look for a 200 CFM flow intake port at .450 lift and a 150-160 cc port volume, will not be hard to come up with. Just consider the larger 2.02 intake valve curtain area will make for a cam choice with characteristics of a smoother idle and higher vacuum with the higher rpm peak. 87 octane fuel too is my preference.

278 advertised duration
234 at .050 duration
108 LSA
62 overlap
.500 lift

This will give you 430 ft lbs and 440 Horsepower roughly


If you want to use smaller valves you will have to lower your rpm expectations to 4800
Expect a slightly smaller cam with 430 ft lbs and 370 Horsepower to get a smooth idle. However if you want to have a higher peak rpm you will need a larger camshaft choice and get a more rumpity idle with the smaller valves.

Another compromise is to run a higher octane fuel.

There are many other variations but I see this recipe as an efficient way to get what you want

[Brian W]

I am a dealer for EQ I can fix you up with a set of hybrid vortech heads.

[Carnut1]

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L48 project thread. Basically the worst Chevy head the 450 305 head with 1.72"/1.5" valves and some straight forward porting. 215 cfm @ .5". My point is ANY chevy head with a bit of work will cover this project. A bit of serious work these junkers beat out small port bowtie vortecs. Thanks Charlie

[bigmike]

OP here. A little more info This engine is going in a 1968 4 speed Camaro I've owned for 36 years. I don't want to add to much horsepower because I do not want to wrap this car around a pole or something bad like that. I run 15 x 7 ralley wheels on it so there is not much tire on the road in this car.The 355 in it was about all I wanted power wise in this car. This 355 has been refreshed a couple times over the years and is very tired at this point. The 355 in it is a 11:1 .100 dome trw piston with old school bowl blended 292 "turbo" head using a Crower solid Circle track cam I see they still make it #00350 268/274, Lift .497/.503,.. 238 /244 @.050 on 107 LCA. I have about 4 intakes for this car and a few carbs. I don't know what kind of power it made but it was enough for me in this car.

My goal with the new 355 is bring compression down to about 9.5:1 or even slightly less to make it more pump gas friendly (91 octane) . Be able to use my old school Gen 1 intakes. I would not mind a bit if the new heads were non EGR as I don't need it for a car what only gets driven in warmer weather. I was thinking about a reto fit hyd roller just because setting valve lash is not my idea of fun in my older years. One of the cams i'm looking at is a Howards reto HYD roller CL110305-08 .480/.480, Duration 282/282 @ .050 229/229, Lobe Separation 108, Centerline: 104. My thought on this cam is this would make enough horsepower for what I want and be very easy on the valve train. I'm open for suggestions on both cast iron and aluminum heads. Thanks for suggestion so far need to read up on some of the suggestions.

[randy331]

A bit of serious work these junkers beat out small port bowtie vortecs. Thanks Charlie

No way. I don't care what your flow bench says, test them on a dyno.

I got an engine sittin here with completely un touched small port vortec bowties on it that's been on the dyno.

I'll test your heads. Bet your heads are at least 50 HP down.

Randy

[Carnut1]

Vortecs have a way nicer chamber but stock don't flow more air.

[randy331]

Vortecs have a way nicer chamber but stock don't flow more air.

So that's a NO on the dyno test ?

Randy

[Rick360]

Which ones have more "Port Energy"?


Rick

[Carnut1]

Vortecs have a way nicer chamber but stock don't flow more air.

So that's a NO on the dyno test ?

Randy

At the moment I don't have the time, money or strength to bang heads with you. It would be nice if you actually taught some of your advanced knowledge instead of an instant challenge. If you had read my L48 thread you would know the 450 heads that I was working on are cracked. I doubt I will ever port another set. They are crap. But I was able to make them flow quite a bit more air than a stock small port bowtie vortec. Now I may not be a rocket scientist but please explain how two similar designs, with similar port volumes will be so different on power production. If you are dead set on a stock vortec challenge I will after I get my schedule cleared, finish up my 081 heads. You know 305 garbage. Thanks, Charlie

[Carnut1]

Which ones have more "Port Energy"?


Rick

The answer would be if they have similar port size the one that flows more air would have more port energy. Make fun now but as long as the higher flowing port is not too fast for the application the heads with higher port energy will make more power. You may not know this but if I want to talk heads, hotrods or engines I call DV, or one of the five ST members I am helping with projects at the moment. True I don't have dyno experience but that will be changing soon. Thanks, Charlie