Hello, I have a 1975 L48 Corvette that had been rebuilt before I purchased it. It has a KC1013R Cam kit put in and I put duel exhaust with Magnaflow on after the purchase. I had the rochester carb perfessionally rebuilt and the original heads had been machined when the engine was rebuilt. I bought a Weiand 8004 intake but is not on yet that will work with the rochester carb. I am going to put headers on, but want to get better flowing cylinder heads. I have heard that even with the  machined original cylinder heads,that they still would not be a great flowing head to use. I hear Vortec cylinder heads sometimes won't work with other parts such as intakes. I am looking for a good cylinder head to work with what I all ready have. I am also maybe starting to do a frame off restoration. I have bought body mount bushings and cross member bushings, driveshaft u-joints, haft shaft u-joints and differential front cushion. I have the body mounts almost disconnected, but not all the way out until I get a lift. I thought I would fill you in on my plan.  I have just seen edelbrock Performer aluminum heads 70cc chamber, 185cc intake runner and 65cc exhaust runner volume, could this be a good heads for the engine,   THANKS Zapparex

|UPDATED|5/3/2013 4:11:33 PM (AZT)|/UPDATED|

Vortec heads will work, and work well.  But you'll also have to change your intake manifold.  Headers will still bolt on.  Valve covers are different; center bolt versus perimeter. 

You'll have to be careful with air cleaner height as well.  Talk to the folks at Jegs about which intake to buy.

You can see the heads bolted on in my profile pic.

Darryl

If you already have an intake that works with your present 882 heads, it'd probably be cheaper to look at something like a set of RHS or Dart iron heads. Way better flow than the old 882 heads. They even outflow the Vortec heads and everything you have will bolt right up and they are perimeter bolt like the old heads. A set of Vortec heads are also limited in the amount of lift they can handle, not an issue with most aftermarket heads.

if you are using the stock pistons you may want to consider a 

The pistons are Sealed Power H31P30, I tried looking them up and don't see anywhere that they are a stock piston. I was looking at the RHS heads and they sound impressive but need more help on which type. I also seen RHS #12302 180cc 72cc, but 64cc is what I should be look at, or so I have heard. Thanks for your feed back. it gives me more to choose from. Zapparex

to calculate the compression ratio you need to know the bore and if the pistons are flat top,if they are dished or crown you need to know the volume + or - c.c. Summit Racing has a good online compression ratio calculator. I believe you should try to get to 9.5 to 1 as a minimum. Hope that helps.

I've got Vortecs and would do it again, but they are not without their limitations and engineering conundrums.  I used my stock exhaust manifolds and the casting bumps on them have to be ground down a bit to clear the valve covers.  Air cleaner height can be an issue as mentioned - I had to use a shorter open element, 12 inch, not 14 air cleaner to clear the hood (PM me if you want more info).  There are not many spread bore manifolds available if you want to use a Q-jet.  I used a GMPP aluminum intake - again PM me.  The center bolt valve covers cause a few problems too: I had to use a longer alternator belt since they are taller and you can not push the alt far enough in to get the stock belt on.  Also, the PCV and oil breather accommodations are reversed - not a big issue but you have to figure out a way to run the PCV hose from the front of the carb to the back of the driver's side cover.  The water temp sensor accommodations on the heads are not the same as original - I ended up installing the sensor in a hole on the manifold.  Finally, as mentioned the amount of valve lift is limited, these were designed for trucks, but there are tricks head builders can use to allow more.  And you have to use self guiding rockers.