My 305 is in the bin, I have a 350 waiting for heads. My guy wants to put 882's on there.

Everywhere I read when I search people say to not use those heads. No where in my search does anyone actually say why other than they are garbage. So why not use them?? Im asking for numbers and proof here.

I cant afford super expensive heads, and I'm getting these free, so if they truly are that bad what options do I have for replacing them with?

 

Check www.chevyhiperformance.com site's Cylinder Head Flow Database, it's linked on the main page.

The 882s flow 205/142 int/exh at 0.500" lift...Vortecs by way of comparison flow 239/150 at same lift.

And then there are AFR 190 heads...262/202 at same lift.

It's not that the 882s are bad heads, there are much better options. The flow numbers don't describe combustion chamber efficiency either, both the Vortec and AFR heads have more modern chamber shapes which can make more power per unit volume fuel than the ancient 882 heads. Plus the 882 has 76cc chambers, running flat top pistons you'll be pushing to get near 9:1 compression.

Sounds like cost (free) is the big factor, so the decion's already made. If you were hoping to feel better about the heads...sorry. They suck.

 

Thanks for the link, looks like plenty of good reading.

Its not the fact that they are free, its that I want to justify like $500 for vortec's or more for AFR's etc... The question I guess is wheather or not its worth paying for different heads. Im not out to have a monster engine or anything, I was hoping for 325-350hp and thats it. Will those heads not get me there?

 

Buy Desktop Dyno or find a friend that has a copy to model engine combos to get a better idea, but offhand (not knowing what cam, pistons, induction, etc. you're running) I'd say you'll make somewhere between 100hp and 300hp at the crank.

 

lol, didnt expect an estimate just yet.

You got AIM by chance????

As far as details go most is still in the air, though I do know inductions is staying tbi, using an Edelbroke intake. Cant tell ya the pistons, saw them today, compaired them to stock ones and was inpressed. (size/thickness wize) Cam is only limited to a crane one, apart from that its undecided. Headman headers I believe with a nice exhaust cat back, only decision there is that hooker costs to much.

And of course the 882 heads.

 

I thought I read on here that 882s are among the worst heads.

 

Yeah, you'll be able to get 300 hp out of the 350 using those heads. They aren't the greatest but when money is a factor, that's what it will be. No need to apologise for being out of cash. In fact, welcome to the line-up!

Or you could pick up a set of 305 heads and follow the instructions linked at the bottom of my sig. Then you'll end up with a set of heads that flow like Vortecs for a total cost of maybe $400.

Keep in mind that if you buy Vortecs ($500) you'll also need a Vortec specific intake manifold and that's at least another $200.

 

The worst part about 882's is the fact that they are smog heads, with VERY thin castings. They have a dual egr passagethat you can see in the exhaust port, and tend run hotter than other SB heads. Even if you find a pair that check out,they'll probably take a **** in any kind of performance application. I think the highest rated HP application they came on was around 220, and cracked in stock configuration. They can make decent power with enough money in them, but it'd be a shame th throw the money away on heads that are so thin.

 

IMO, get the best heads you can afford now. The labor cost of pulling the 882s later will eat up the amount you saved on them unless your doing the job yourself. Without good flowing heads, you wont have much more power than the 305 your replacing.

Invest in Desktop Dyno 2000 and do a little testing with different heads with your planned combo. You'll get an idea of the performance hit you'll take by using the lo-po heads.

 

WildmanDRL, I have DD, but I dont know enough to run it yet. Like where do I find the valve sizes for heads? I have flow files for most heads, and a handfull of cams as well, just need those valve sizes.

ZZsmpch, are they really that thin? My guy was picking them just because they were thicker than normal *newer* heads. The block as well as the heads were made in the 70's if that helps.

Sitting Bull, vortec isnt an option. I was looking at going TPI during the rebuild in which I would have used vortecs with that S-D intake, but I decided to keep tbi so no vortec.

Just curious, how do 882's react to porting compared to stock 305 heads?

 

Guess you didn't bother actually reading the Chevyhiperformance link I posted above...the valve sizes are listed. 1.94 intake 1.50 exhaust.

 

Yeah, the 882's are a dime a dozen because they are so common. they've been around since late 73. They are better than the newer 624's, but aren't really that good for anything other than a stock replacement. If you want to go with older castings, try to find some 487's, 493's, 993's, or 997's. For the money, you won't find a head that flows like the Vortecs do. But yeah, the 882's run hot and crack. I wouldn't waste money on them.

BTW, the 882's are 1.94, 1.5, with 74-76 cc chambers.

 

Go to the head manufacturers web sites and get the specs on the heads you are interested in for aftermarket heads. For stock heads, do a little searching for sites that list specs for different castings. I know mortec.com has SBC specs but I'm not sure if has head specs. Print them out for future reference.

 

Check this page for stock casting valve sizes

http://www.montecarloss.com/SSThunder/SBCinfo.html

 

If all you want is transportation then go with the free 882's.
But keep in mind there is a reason why they were free.
If you plan to be able to beat any 305's
Pick just about any of the performance factory casting

On my 350, 882's limited my performance to low 14's.
Just changing to Chevy vortec heads and intake chopped over a full second from that.
I would suspect that the flow ratings shown in the chevy hiperformance article are with 2.02'sx1.60 with a 3 angle valve job. The stock ones don't flow this much.

I wouldn't even bother trying to port them. A set of 305 "416"
or "081" with 1.94's would be much better after porting.

A set of untouched camelback's would be like night and day.

There are some "open chamber" smog heads that are worth mention 487 441(x) etc but 882 is not on that list.
Find a 58/64cc based head and start with that.

 

Kevinc, yes I realised the stupidity of my question about 30 seconds after I posted.

Im gonna wait and have another chat with my guy and see what his reasons for the 882's are. Then see what we can change to (whatevers laying around in his shop pretty much).

 

If you reread my posting you will see that I am NOT recommending Vortec heads at all!

What I am recommending is that you pick up a set of 305 heads from the junkyard--cost $25--and port and polish them yourself. THEN you will end up with a set of heads that flow like Vortecs but cost A LOT less.

Vortec heads and a carb manifold = at least $700

305 heads, ported/polished/1.94 intake valves and all new hardware = $400

Your current intake manifold will work perfectly fine with the 305 heads.

So, what is easier to swallow for poor boys like me and you? $700 or $400?

As I said, follow the link at the bottom of my sig

And as F-Bird'88 said, those weak 350 castings won't get you into the 13s :nono: