Ive run out of upgrades for the 350. Only thing left stock are the heads. Before I tear them off and spend 800 bucks on new heads, how much of a gain will aluminum heads REALLY get me? I want seat of the pants gain, not dyno results. Ive got plenty of other expensive habits and 800 bucks had better drastically change performance.

 

Are they stock 350 heads? If so you should see a minimal 25-50hp gain, depending on the cam that is in it. I know you said you have an RV cam, and you don't know what the specs are. Do you have a sound clip of the car? It's pretty easy to tell how aggressive the cam is by listening to the exhaust...

IMHO, I would say either Patriot Performance 190cc aluminum heads, or their worked over vortech heads coupled with a set of 1.6 ratio roller rockers to give you a little more cam lift. That combo could easily net you 50-75hp over stock 350 heads.

 

50-75 horse? That is a noticeable difference. I may have to look into this as a winter project. Here a few new questions...

You mentioned cam. My cam is mild, it doesnt lope much. Nice steady idle with very little rumble. Should I replace it also?

Also, what heads do I need to look out for? There are plenty of em on ebay. My block is a 2 bolt that originally came from a 1974 truck. IIRC post 94 heads wont work because of flow issues. Any quick way to tell?

Lastly, will my 600 cfm carb still be enough if I go with new heads?

Thanks. (I know there only seems to be 2 or 3 people left around here that can even answer this!)

 

The material the heads are made does not make much difference in the power output, the difference comes from how the heads are designed. The only explicit advantages of aluminum heads are considerable less weight and about 1 point more compression tolerable due to better cooling.

 

Are there aluminum heads that are only slightly better than stock? I dont wanna spend the money and then find all I did was swap steel for aluminum.

 

It all depends on the head design. Each company making heads has many various designs available, depending on what type of use they are going to have. For street use you can go with either iron or aluminum, for racing aluminum would be a better choice, if for no other reason is that they are lighter. If you expect a noticeable gain by changing heads you need to change the cam so that both heads and cam have the same
characteristics (matched). If you want to save money, and get a decent power gain get a set of cast iron Vortec heads from GM, and better cam. You will also need a different intake manifold. World Products, http://www.worldcastings.com/product...evrolet-heads/ makes iron heads that will stand up to most aluminum heads.

 

I highly recommend against the GM performance Vortecs. Patriot Performance offers fully worked Vortecs for only $30 bucks more. They include larger intake valves (2.02 vs 1.94's), improved flow properties, stainless steel valves, springs and retainers good for up to .575" cam lift, and dual intake and valve cover bolt patterns, meaning that you can use a standard SBC intake manifold with them, along with perimeter or center bolt valve covers. They're aluminum heads are about $200 more a set.

I don't want to sound like a Patriot Performance leg humper as honestly I've never used their products and there are plenty of head manufacturers to choose from. However, for what you get, they look to me like a great value and I plan on purchasing the Vortecs for my Camaro.

The cam, it's up to you. If you want more power, then go for it. It's just going to be some extra work but if you're already doing the top end, now is the time to swap it out.

You've been having cooling issues though, correct? I would upgrade the radiator and fan before adding any more mods. This just increases the potential to overheat. Not to mention Aluminum heads don't like getting hot, if you do decide to go that route.

You also have to consider how many miles are on your motor. Sometimes it's not a good idea just to slap a cam in as you run the risk of spinning a cam bearing if your engine is high mileage.

IMHO, I think you would be happy with a set of 1.6 ratio RR's and the Patriot Performance Vortecs, after upgrading your cooling system. This combo should net you around 50 HP, which you will def. be able to feel.

 

The engine has less than 5k on it so Im not worried about blowing out old rings with a new set of fresh heads. You make a good point that is often overlooked. Yeah, the cooling issues are a whole other ballgame and need to be addressed but thats just a radiator.....

I was hoping to just bolt on a set of heads, maybe a cam..........it looks like just picking the heads will be a winter project in and of itself. Hell, I can get a 383 crate for 2500 bucks.......Id rather do an engine swap than pull heads.....

 

Where are you getting a 383 crate for $2500? What kind of power is it putting out?

 

ebay has all sorts of crate engine deals. I wasnt looking real hard, they may have been short blocks.....