Just curious what your thoughts are on this. My heads are the stock 5.3L heads now. The very last manifold bolt broke off in the drivers side head causing a bad exhaust leak. There's no room to fix it without removing the head. So, might as well put some new heads on right?

I'm not looking to spend very much, just a budget upgrade that will compliment boost. I figure the 241 heads flow a little better, have bigger valves, and will drop my static CR a little bit. Sets of these go for $200 or less, pretty affordable. The plan is a front mount turbo putting down around 500+rwhp. Will be running a LS1 or LS9 cam.

Any downsides to using these heads? Valve shrouding?

Thanks!

 

Just to add, this will be my daily driver, so good driveability and mpg are important. Sounds like a higher CR is good for this. What would the CR be for LS1 heads on a 5.3L with the stock thickness gasket?

 

If you pull the inner fender out and use a left handed drill bit that back bolt is no problem to get out. I've done it a few times. I am a tech at a chevy dealership and its a fairly common problem. Not a bad idea to change the heads, but not neccesary to fix you leak.

 

I don't know what the chamber size is of those heads, but I believe they came on the LS1's and will be larger than your 5.3 heads. The larger chamber size will cost you compression thus hurting drivability some out of boost, which you don't want for your DD. Honestly, I wouldn't pull the heads unless your going to at least put on a set of better flowing heads. You probably wouldn't see much if any improvement from the flow of these heads over your stockers, I doubt enough to even offset power loss from the compression loss. Since your on a budget, I would look into the SDPC CNC'd 5.3l heads. You would keep stock compression and it would wake the truck up alot out of boost. You can also find some used 5.3 heads that have been CNC'd pretty reasonable on LS1tech, the N/A 6l guys run them in the cars to boost compression. Pair the 5.3l heads with LS9 gaskets for boost and ARP hardware and you will have a very stout boost ready 5.3. Also I wouldn't consider an LS1 cam, go with the LS6 cam over the LS9 for a turbo 5.3l. Do some searching, the 02+ LS6 LOVES the boost in a 4.8-5.3 for some reason.

 

Thanks for the tips. If I can get the broken bolt out then I wont be swapping heads. The truck already has an '00 LS1 cam, which IMO is leaps above the stock 5.3 cam. I have an LS9 cam on the way which I have read is great for boost.