10088113 Corvette Aluminum Heads

10088113 Corvette Aluminum Heads
10088113 Corvette Aluminum Heads


10088113 Corvette Aluminum Heads

The 10088113 Corvette Aluminum Heads are easy to find and one of the few aluminum heads GM put on a production Gen I small block. These are one of Chevrolet better heads for small block. They got most of the features we have come to count on in a good head from the aftermarket. Including screw in studs, guide plates, 1.94 intake valves, angle plug, D shaped exhaust ports and 58cc combustion chambers. A great little head that flows well and will make good power on most small blocks. It might not be the best choice for your flame thrower 383 stroker engine but this is a good one. It is also a great upgrade for just about any 305 even ones with good heads. These little babies will take more compression flow better and hold on longer than any 305 head.

“Wait What about the 305 Vortec” you say. The Vortec head has some good points and may or may not flow more than the 113 but they are not aluminum and they dont come with screw in studs and guide plates. The vortecs will be off to the machine shop to match the bolt on performance these can provide.

The 10088113 Corvette Aluminum Heads have the standard intake bolt layout. They use all the normal gaskets and bolt right up to any small block. They work in most applications and are a big bump in power on most any stock headed small block.

Lets look at the flow numbers

What about flow. Well here are some flow numbers from the stock heads and some reported on the net many of the stock heads flow the same but its clear a good porter can make the heads flow well beyond the stock flow at higher lift rates. With some good port work it is possible to get about 211-243 cfm and that is good for 450 to 500 hp. Certainly not bad and in stock form the 182-198 cfm is good for about 400 N/A hp. This is one reason I am writing this article. The Power these heads can deliver is not as much as the stock vortecs unported flow. The L31 heads can flow 216 cfm in stock form and work great without porting and make good power. With some minor machining to allow for more lift the heads can produce 450 in as cast form.

Lift……Stock……Lightly Ported 10088113 Corvette Aluminum Heads
.100″     .63        .67
.200″     .117       .148
.300″     .163       .194
.400″     .186       .212
.500″     .196       .213
.600″     .197      .212

Here is another popular list of none ported flow numbers

.200 – 114.8
.250 – 135.6
.300 – 150.5
.350 – 162.4
.400 – 172.3
.450 – 178.2
.500 – 182.2
.550 – 183.2

.200 – 89.9
.250 – 104.3
.300 – 115.0
.350 – 126.8
.400 – 135.3
.450 – 139.6
.500 – 142.8
.550 – 145.0

Here are some numbers from a mildly ported set of heads. I have herd of higher flow numbers in the 300 range with 2.02 valves but that sounds to good to be cool.

.100, 81.4     .100, 68.2
.150, 110.2    .150, 98.1
.200, 139.1   .200, 113.0
.250, 159.8   .250, 138.6
.300, 179.0   .300, 157.5
.350, 193.8   .350, 168.5
.400, 207.2   .400, 177.9
.450, 216.0   .450, 185.8
.500, 220.5   .500, 189.0
.550, 223.4   .550, 193.7
.600, 224.9  .600, 193.7

The L31 stock Vortec heads are hands down the best flowing heads gm ever put onto a small block that’s is production. These numbers are common flow numbers for stock vortecs of course these heads work very well.

Intake     Exhaust

.1   66        57

.2   129      101

.3   186      136

.4   219      149

.5   216      155

Performance is more than just flow numbers

With all these numbers its hard to tell what heads to install on your engine. Well the 113 heads are not a bad choice. One thing to think about that these heads come with push rod guides and screw in studs. These heads are bolt on and make a big choice a little easier. With Vortec heads it will cost additional money to machine the heads and to make them ready for more lift. The 10088113 Corvette Aluminum Head will also require the need for additional lift just as the Vortec do. But the 113 heads can take as much as .525″ lift without machining the guides and even more with the guides cut down. The guides are easily cut with proper tools.

Comp cams makes a good tool for this job that is reasonably priced it cost about the same as a trip to the machine shop for the same job and can be done to many heads. With the proper cutting of these heads and bee hive springs and retainers they can take up to .550+ lift. That is enough for most small block heads to make one heck of a powerful engine.

How it all comes together

Once you have the heads ported and a little more lift you can make a nasty 500 hp pump gas motor that is worth all the effort. This is the range of most after market heads much larger. Now that is not the goal of most of us. Affordable engine that means 400 hp and done with just a new set of springs and the factory pistons and the proper cam along with other supporting parts and hardware. Now that makes them one of the best heads chevy has ever made.

Here are a few pictures of a fresh set of 113 pulled from a running corvette motor. These need to be rebuilt but are in great condition. Note the angle plugs and small chambers. This shows why the 1.94 valves were used. Clearly see some room around out outside of the valves that allow for less shrouding and more flow with a smaller valve.

20160207_192830 20160207_192727 113ports

What can be done to make them even better

With larger valves and some major port work you can make for a lot more power. These have been ported into the 300 cfm range. Which is enough to make 600 hp in a perfect world. Now if going for that kind of power your going to have major issues with the 113 heads. But it does make it able to make a better power range with less duration and less lift. Allowing for a more gentle cam that is better suited toward street driving. Still not a replacement for AFR or Brodix track 1’s but still a great head for a budget build. If you can do a small amount of port work on them you can make a motor that really sings and produces good power all over the rpm range.