I've got late-model Vortec heads on the motor now (based on accessory hole measurement guides I've read). They've had some basic porting and polishing done, but nothing too drastic. I'd like to bolt-on some added power and figured heads may be the best way to do it.\


What would be a "best bang for my buck" way to go about it? Different stock iron heads taken in for serious re-working? Alluminum heads (noting I need to be price-conscious)?

What kind of HP gain could I expect with a moderate $ head upgrade?

If I go with new heads, will the exhaust ports line up fine with my headers?

Can someone point me to the right place to find the stock stats on these heads? The block casting indicates its a '99 350. Where are the castings on the heads?

Thanks all!

Your heads are plenty good. How much are you looking to spend? A cam change would be a cheap upgrade with maybe 1.6 roller rockers. To get a really noticeable difference in heads, you would be probably spending $1K, and while still having the same cam, might not notice much improvement.

I have 400hp from my heads, and there's still plenty of room for a bigger cam.

what cam are you running? our build, other than standard bore, sounds very similar right down to the intake. What work did you do to the heads (if any)?

Do you have the stock head info (valves size, CC, etc)? and what CAN I go to in valve size?

dart iron eagles!! cant beat the price ,and they flow alot more air !! the exhaust is in standard port location..you will have to change the intake though.NO PORTING NEEDED, for a substantial increase in power.

can't use an Edelbrock AirGap on Dart heads?

well, i think i just found out that I may NOT have Vortec heads. i read something that said all Vortec heads have a saw-tooth casting in the end of the head at the front. Is that true?

Someone that had worked on the motor used the term "grenade" heads or something like that. Does that have any real-world meaning?

Forget the castings on the end of the heads. Vortec heads all have one thing in common: no intake mounting bolt holes near the carb. They only have 2 bolt holes on each end, and they go straight down instead of angled. This is why they use a special manifold.

If you still want my engine specifics, PM me, and I'll give you the dirty details, I just don't have it all on me right now.

not all of them do. some have just one big hump in the middle rather than 3. I think the one with the saw look is the 062 and the other is the 906 casting

http://www.twotonelive.com/chevelle/head.jpg

here is a pic of the driver's side

The true, desirable Vortec heads will have either a -062 OR -906 casting number along with the manifold bolt pattern as described by Bowtie.
Any other "center bolt" valve covered GM SB iron head is junk for a performance application.
Your picture clearly shows those are NOT Vortecs simply by the angle of the intake bolt!
Good news is you can reuse that intake on a good set of aftermarket heads.

Post back your heads casting numbers and we will tell you just what they are..

pdq67

Any other "center bolt" valve covered GM SB iron head is junk for a performance application.
Your picture clearly shows those are NOT Vortecs simply by the angle of the intake bolt!
Good news is you can reuse that intake on a good set of aftermarket heads.

The better news is you can scrap-bin the heads AND the intake, install REAL VORTEC heads and intake for dirt cheap, and make the engine run much better.

You are currently running about the WORST HEADS EVER OFFERED BY CHEVROLET for performance use. Putting on Vortec heads and a matching aftermarket intake manifold from a reputable company is the best money you could spend on that engine.

The better news is you can scrap-bin the heads AND the intake...

There's nothing wrong with his Edlebrock Air-Gap intake. :(
Like I said, it just needs a better set of heads.
I'm not arguing the Vortec recommendation...I've built plenty of Vortec combos. But why start completely over? Put that $$ towards a set of aftermarkets and reuse the Air-Gap.

Schurkey,

What heads are they that are SO bad, please post the number's back so's I will know too!!

pdq67

There's nothing wrong with his Edlebrock Air-Gap intake. :(
Like I said, it just needs a better set of heads.
I'm not arguing the Vortec recommendation...I've built plenty of Vortec combos. But why start completely over? Put that $$ towards a set of aftermarkets and reuse the Air-Gap.
Now I understand what he meant by "can't use an Edelbrock AirGap on Dart heads?". Sorry--you're right, that's a fine manifold. I suggest he sell or trade it to offset a Vortec manifold/head package. He could keep the manifold and install better non-vortec heads, but I have every expectation that he'd spend more money and likely get less gain.

The Vortec head isn't the end of the world for performance--but--they're VERY GOOD and the price is WAY reasonable at any scrapyard. It's the king of "bang for the buck".



What I wanna know is who installed pre-Vortec centerbolts on a '99 block?

Schurkey,

What heads are they that are SO bad, please post the number's back so's I will know too!!

pdq67
Any regular-cooling-flow iron center-bolt heads prior to the '96 Vortec. So--any '86 to '95 iron centerbolts except the LT1. About half the intake port is blocked off by the valve guide to promote "swirl". The chamber is nothing special, either.

When GM dropped the non-Vortec centerbolt head from the 350 HO engine and installed Vortecs instead, they gained a rated 30 hp. 30 hp was an additonal 10%! I suspect it was actually way more than that.

dart iron eagles!! cant beat the price ,and they flow alot more air !! the exhaust is in standard port location..you will have to change the intake though.NO PORTING NEEDED, for a substantial increase in power.

Im using the Dart iron eagle 165cc s/s heads that where $654.94 shipped from Competition products on-line. Great deal and they make my heavy chevelle run 12.4's with a mini-blower on pump gas. For such a small head they perform great.

Doesn't Summit have some bare heads on sale way down the line now??

pdq67

I've got a friend who swears by his World Sportsmans. Does anybody have any feeling on their performance? Do they have any compatibiulity issues as mentioned with the Dart Iron Eagles?

The true, desirable Vortec heads will have either a -062 OR -906 casting number along with the manifold bolt pattern as described by Bowtie.
Any other "center bolt" valve covered GM SB iron head is junk for a performance application.
Your picture clearly shows those are NOT Vortecs simply by the angle of the intake bolt!
Good news is you can reuse that intake on a good set of aftermarket heads.

Bill's right. Unless you want to toss another wad of cash for a new intake, get a set of decent heads and re-use what you have.

Stock (1.94/1.6) home ported heads and I went 13.2"s @ 103. I then went to 200cc "aftermarket steel heads" (2.05/1.6) and went 12.3's @110.
I think an aftermarket set of steel heads with the same chamber volume and 180-195cc heads with 2.02/1.6 valves would be a big jump in power with no other changes (30-50hp IMO).

I've got a friend who swears by his World Sportsmans. Does anybody have any feeling on their performance? Do they have any compatibiulity issues as mentioned with the Dart Iron Eagles?
the sportsman heads are old school!! they are similar to a ported fuelie head!!
if you do some porting they come alive , but the new 200 iron eagles tear them up flow wise. they have the same exact bolt patterns though.

the sportsman heads are old school!! they are similar to a ported fuelie head!!
if you do some porting they come alive , but the new 200 iron eagles tear them up flow wise. they have the same exact bolt patterns though.

the sportsman really wake up when ported right as do the older fuelie heads. Problem you know how to do this or get a "bro deal" for porting it's going to cost you. Might as well just get some aluminum heads like afr,brodix etc.

Competition products is having a deal right now for the older dart heads.