mountainshark76

Hi all
i have both 882 and 993 heads that i can rebuild they look very much the same, does any know the differance between them? and which one is the better performance choice
:conehead

ORVette

Try Mortec.com. 882's are listed as 74-80 350/400, 76cc chambers. 993's are listed as 72-73 307/350, 75cc chambers-and-that casting# with "Hecho en Mexico" also is current 350 Goodwrench crate motors, 75cc Chambers. I'm pretty sure they both used 1.94/1.50 valves. If the 882's are cast prior to '77, I think they are a little heavier casting. Hopefully one of our head experts will check in.

Tom454

Here is a quote from the back of my Cheerios box...

"In 1975, a lighter head was released sporting 1.94 I and 1.50 E valves: the casting number was 333882. The 882 heads were installed on the 350 ci and 400 ci engines (400 heads had steam holes). The 882 castings had a double heat-riser passage [single on the intake side, double on the exhaust side] and were prone to cracking because they ran so hot. If you have these on your engine, get rid of them."

That should answer the question?

Tom

john's '81 mouse

Use the 993s, the 882s as has been said are thin castings, prone to cracking when they are subjected to any overheating. I've been told that even worse than the 882s are the 624 heads which came on my '81, and which I am still using. In his book on S/B Chevys, David V. says to toss both the 882s and 624s when building a performance small block. He goes on to say that the 993s are a good thick casting that should stand up well, if you want to run OEM type heads.

Ganey

The 993 are good. The ones made in Mexico may not be as good as the USA ones. 882 not rec..

Alwyn678

[quote]Here is a quote from the back of my Cheerios box...

"In 1975, a lighter head was released sporting 1.94 I and 1.50 E valves: the casting number was 333882. The 882 heads were installed on the 350 ci and 400 ci engines (400 heads had steam holes). The 882 castings had a double heat-riser passage [single on the intake side, double on the exhaust side] and were prone to cracking because they ran so hot. If you have these on your engine, get rid of them."

I gotta agree..I had those heads and They SUCKED.....




[Modified by Alwyn678, 10:01 AM 1/10/2002]

daily_driver

hmmmm

all my cheerios box has is some stupid games on it

:confused:

jrh74cp

And that is why my 882's are resting on my garage floor while my new Vortec's are being install on my car. They should make nice boat anchors next summer.


[Modified by jrh74cp, 1:02 PM 1/10/2002]

mountainshark76

thanks all for the help, and big thanks orvette for the mortec site i did not know about them. i entertained myself for a couple hours :D :D

KenSny

882s - if on an L82 came with 2.02/1.60 valves, screw-in rocker studs, and guideplates. I know. I've got a set off now.

Tom454

My Cheerios box is dated (copywrite/published) 1991. Maybe those L82's are newer?

Cheerios box:
Motorbooks International
How To Build & Modify Chevrolet Smallblock V-8 Cylinder Heads
David Vizard

The reason I quoted the book is because I can't personally testify on the subject via experience... and I don't
believe everything I read. Even being in the business, there is a good chance that every version of every part will not pass through your hands. So... there is always a possibilty that there will be exceptions... David Vizard needs to be informed. I'm all set.

KenSny

Tom, I got a lot of Vizard's books also and noticed the same thing. The Chevy V8 interchange manual also does not talk about the larger valves. However, these are the original (date verified) heads from my '75 L82 -AND- the GM "specs and restoration guide" for 1975 Corvette clearly states that the L48 and L82 used the same head, BUT were configured with different valve sizes, etc (pg: Principal Components, Power Trains-7 printed Sept 74). Now down to the important stuff ---- are those plain Cheerios or the Honey-Nut Cherrios? ;)


[Modified by KenSny, 3:12 PM 1/11/2002]

rayray

I know that alot of people don't like the 882's but I also know there is alot that like them. I've seen some 882's with 2.02 / 1.60 valves supposely from the factory. I have taking a set off a 400cid from a '79 van that had 1.94 / 1.60 valves. I've heard that it's common on 400cid small blocks.

KenSny

The big problem with the 882 heads is the double heat riser crossover passages. These are a major weak spot in the center of the casting, and because of all the exhaust they run real hot and are very prone to cracking

Tom454

They're Honey Nut... not standard. That's why all the confusion.

Anyhow. I quoted the book because I wanted to make it absolutely clear that it was not my own opinion... but someone elses.
Generalizations like that tend to bite you in the butt, so I try not to make them. I believe all you guys on the issues..
no problem. The point I was trying to make is that the 882's have the heat cracking problem... I wasn't focusing on the rest of the info provided by the book (e.g.- valve size, screw in studs etc.), it just happened to be part of the quote. It's not relevant.

Next time, I'll use my Frosted Mini Wheat box.

Tom

KenSny

You are right.

I would recommend NOT reusing 882 heads for any kind of build.

I just brought up the "valve" point because so many books seem to miss it. I wonder if the 882 heads with large valves are such a small percentage that they are not very common in the bone-yards? After all that's where Vizard
does most of his shopping.....

BTW: I'm not going to use mine for boat anchors. I have a standing offer of $300 for the complete heads from a local chap - so they must be worth something to someone for something, don't know what, but I'll sell.....



[Modified by KenSny, 8:43 AM 1/12/2002]