dgruenke

I have a few questions about some engine specs for my 1976 L48 and hope that you guys can provide some answers.

1. What is the cc spec for the head (i.e. 64 cc, 67 cc, 72 cc, etc.)?

2. What are the stock valve sizes?

3. If I go to larger valves (2.02 and 1.60) will the new valves fit right in or do I have to do some grinding?

4. What is the intake runner volume on the stock heads?

Thanks.

45ACP

1. 76cc nominal
2. 1.94i 1.5e
3. It would take some work
4. I believe they are 150cc

They are ok for just driving around, but if you want to go looking for more horsepower, invest in other hardware. I got rid of mine years ago when I modded my engine in '92. I have the rough equiv. to Edelbrock's "Performer RPM Package", except I used iron heads (which is what was recommended at the time).

page62

Nasty 76cc smog heads. Prone to cracking. Not worth messing with. Pull 'em off and send 'em to the smelter. (The L82 heads are the same casting with bigger valves and valve guides.)

Personally, I'd like to have a set of aluminum L98 heads from a C4! :cool:

dgruenke

Thanks for the info. I am going to do an overhaul right now, but must stay within a budget. :( Therefore, I was looking at doing some minor mods to the existing heads to get a little more air. Any suggestions, or just get rid of them?

KenSny

882 heads are not worth doing any work. They are prone to cracking because of the 2-port heat passages. You will not realize any gains for your effort of "doing some minor mods to the existing heads to get a little more air." If you can't afford to replace them now then decarbon them and reinstall..... and if they are blowing oil maybe replace the valve seal umbrellas. Do the work yourself otherwise you are dumping money into the trash can......

Now - if you could swap someone (for no $$$) for the larger valve L82 heads then maybe ok. Otherwise bite the bullet and get rid of them.

BTW: 333882 heads have 76cc chambers, 151cc intake runners. L82 heads are the same as the L48 heads except for 2.02/1.60 valves and guideplates. Also I have not verified this but someone told me that L48 heads have press-in rocker arm studs, whereas the L82 heads are screw-in studs. (????)


[Modified by KenSny, 11:54 AM 3/24/2004]

dgruenke

Thanks again for the help.

Boofers

Check out this link for casting number info...
http://www.chevytalk.com/tech/engine/SBC_Heads.html

dgruenke

That's a great site. Answers nearly every question about SBC heads. Thanks.

pillowmeto

vortec heads(junkyard trucks) are a great value if you want to get some performance, but arent looking for massive power

MAtt