well i am looking at a set of 416 heads for more compression. well i was doing research on them and i found out that they have only 1.84 intake valves. I dont really want to pay a shop to cut in bigger valves. so i was talking to one of my friends and he said that he could get a set of vortec heads out of the juck yard, for 'cheap' I couldnt seem to find out what combustion chamber the vortec heads have. do you think i should bother with vortec heads, or stay with the 416 heads and get a 1.94 intake valve put in?

 

All depends on your wallet, prefferences and the results your looking for.
I would avoid Junk YARD vortec heads. If they're in the junk yard
they are probabily worn out or cracked. Being that new castings are so cheap to buy why bother. New Vortec heads need some preparation before you can use then on your motor.
Search the posts on the subject, all the info is there on what to do.
The 416 heads have small valves 1.84 x1.50. and full sized ports.
In stock form they have 58cc chambers but flow less that a stock 350 head.
but.... if you install 1.94x 1.50 or 1.60 valves and fully port these heads you will have a dynomite budget street/ strip performance head that can/will rival some after market heads including Vortecs. Depending on your porting efforts.
If you enlarge the bowl with a dye grinder under the valve and relieve the chambers for the 1.94 valves your self, the new valve job will be routine and shouldn't need to cost any more than a 1.84x 1.50 valve job.
I have done a few of these heads and have posted at length on the subject. Search my posts. Search Sitting Bull's too. good pics.

 

i read your posts last night and they were very helpful, but thats also what got me thinking. i am gonna look at getting 416 heads and have 1.94 valves in. how much will do you think a valve job will cost?? thanks for all your help!!

 

I can't tell you cause I get mine done cheap (er) {friends in low places helps}

Best to phone around to local recommended automotive machine shops in your area, 'cause reguardless of what I tell ya
they will want their $price$ I'd say $150 US +/-
for a basic valve job. Look for a shop that is recommended and has good equipment. Good work deserves a good fair price.

Note: the L-31 350Vortec heads #062 and #906 are 64cc's
the 305 vortec head is a different beast.

 

What kind of a boost in compression could you expect? Could you run 58cc iron heads on a 350 with pump gas?

 

NtCchrist:

the short answer is yes (on premium fuel)

How much the compression ratio will increase depends on
exactly how high the compression ratio is now on a/your 350.
Dish pistons? flat tops? domed pistons? deck height?
all these things effect the outcome.

an example is if your 350 has a true measured cr of 8.3:1
with 76cc heads the 58cc heads would make it 9.89:1
all else being the same.

10.3:1 is about the limit with sunoco 94 in our area
maybe 10.4 or 10.5 with a big cam.
Aluminum heads will allow a little more.

You can download a good compression ratio calc from
www.download.com
its called engine cr 1.0
Just go there and search for "compression ratio"

 

In the Vortec's case you will have the ability to make more power over the 416's because of a few nice features that have been worked into the Vortec's. Unfortunately, there will be some effort to make them work with your current setup.

 

could i really make more power with the vortech heads??? i was thinking that the smaller combustion area of a 416 head could make up some of the flow loss to the vortech. i think i would rather use 416 heads, or something similar cuz i dont want to make my setup work with the different vortech heads. what do you guys think??

 

A fully ported 416 head with big valves will keed up with a out of the box vortec. for a little less.
But YOU have to "fully port the head" a litttle pocket port job will not cut it here. all you have to do is put the effort into it.
You can't pay a shop to do it. Too labour costly.
If your not willing to port these heads, get he vortecs.

 

well i got another question, how big of valves can a shop cut into 416 heads??

 

While 2.02x 1.60 can be fitted. There 2.02 will unnessessarily weaken the casting.
No performance advantage over the 1.94.

Do the 1.94 x1.60 and you can tell every one what ever you want. Do a generous porting job and they'll believe it.
Yours and my lil secret...

 

pskel350,

F-Bird is the champ when it comes to getting the most bang for your buck out of 305 heads. I followed his advice and have a set that I'm gonna be keeping for a long, long time

Follow the link at the bottom of my sig. It's full of pics and shows you how to it yourself

 

From what I have noticed, the intake manifold after market for 416's are substantialy cheaper than for the vortec. I have both heads sitting in my garage. For economical standpoint I went with the 416's for the smaller combustion chamber and the cheaper intake manifold. Buy the valves yourself at enginekits.com they have good prices on on valves I think I paid 55 dollars for new intake and exhaust valves. take them to the machine shop with you and simply ask them how much.

OOOHHHH it helps to bring a box of donuts too

 

Sitting Bull: that link to the posts on porting and polishing 305 answered a lot of my questions. i think that 305 heads will give me enough performance for my buck.

Radiateu2: yeah i have started to notice that if i use vortech heads i am gonna have trouble getting the intake i want without spending tons of money. thanks for the advice.

 

id suggest porting the 416 heads if your on a budget, seeing that people have ported them close to vortec specs, plus you get the added benefit of higher compression than vortecs, and you can use a traditional SBC intake manifold. by the way, if you want to get the low down on vortec heads, pick up the january 2003 issue of chevy high performance magazine. they have a really nice article, and one of the first things it states is to stray away from the 906 vortec heads, the ones your going to find on some earlier (96-98) trucks and such, something with their exhaust seat that ruins 20% of the flow or something along that line. just some advice in if you want to get vortecs, they have pictures and nice depth descriptions of how/what you need to modify to fit in new valve springs, or use with a higher lift cam.

 

Some "906" vortec heads have pressed in hardened exhaust seats. Like an aluminum head. These are mainly used in heavy trucks, industrial, propane applications. There may be a machined lip in the casting when the seat meets the casting under the valve. this lip edge can be smoothed with a die grinder.
Most of the heads have the normal "flame hardened" exhaust seat. Like on the 062's. Other than that they are the same.
All the Vortec heads benefit from a minor smoothing and cleanup of the exhaust port and bowl anyways. Good for about 20cfm.

Seems some of these writers in the Hot Rod mags aren't really into cars and get a lot of misinformation sometimes. Or take the info they get , out of context.
Sometimes you have to take the stuff they write with a grain 'o salt. The 906 Vortec head is a good head to use.

 

i have a set of 416 heads, ported and gasket matched by yours trully.
i will install them on my 350, it cant be bad. the old heads appart of having the valve guides leaking (on start) have the most terrible specs:
1:74 and 1:50 valves, a huge 76cc combustion chamber on top of dished pistons.
having 1:84 / 1:50 valves with 58cc. chambers CANT be worst.
Fernando