Cylinder head recommendation for 5.3

[DCarl019]

Hello everyone,

Could you guys help me with some recommendations for a cylinder head upgrade on my 5.3. I'm currently running the stock 706 heads with a BTR truck norris cam, TBSS intake manifold and long tube headers. The truck runs great and makes good power but I'm looking to take it up a notch with better heads. I use 95 octane pump gas which is the best we have where I live so something to increase compression would be nice. Any tips? Maybe a different OEM head, or something like trick flow or summit? Thanks!

 

[strutaeng]

Those ARE the preferred heads that increase the compression slightly. The factory LS heads flow better than anything else out there for the buck. Which simply means they can make a lot more power than stock or stock with mild mods.

I don't think you will gain much, if anything, by swapping to aftermarket heads with the mods you list.

Aftermarket heads are pretty spendy also. You could probably almost punch out your 5.3 to 5.7 displacement (or do a stroker, or swap a 6.0) for that money.

 

[swathdiver]

Yep, what he said! ^^^^

Overhaul the heads, increase the compression by shaving them, using thinner head gaskets, etc. Maybe some minor port and bowl work and send it.

Then it's on to gears and cubic inches or power adders.

 

[strutaeng]

Yep, what he said! ^^^^

Overhaul the heads, increase the compression by shaving them, using thinner head gaskets, etc. Maybe some minor port and bowl work and send it.

Then it's on to gears and cubic inches or power adders.

That's a good point!

I had some stock 317 heads checked, cleaned and remachined by my local machine shop a few months ago. These were going into a 6.0 that bought flat top pistons so I didn't really need them milled to bump compression any more, just cleaned up. But that would have been an option for sure. I believe it was $400 for everything. I'll double check on the price later.

Ditto on the re-gearing.

 

[Joseph Garcia]

You want more power? Install a supercharger on it.

 

[justirv]

You want more power? Install a supercharger on it.

^^^^^^^^^^^ This, a S/C AND not increase your compression ratio... if a bore/stroke or 6.0L (up to 408 ) is not in the cards, gearing is a more economical way to get things moving.

 

[Marky Dissod]

All the above advice is sound. Specifically, I would rather spend money improving the heads you already have

... gearing is a more economical way to get things moving.

Since you posted in the GMT800 forum, I'll just go ahead and recommend 4.10.

 

[DCarl019]

Thanks for your responses. A supercharger really isn't a consideration as I'd love to keep it all motor, however a stroker kit does sound very interesting. BTR has a stroker kit for a 5.3 which I'll definitely be looking into. My 5.3 is in great shape and going the stroker route will definitely be cheaper than building a 6.0 swap where I live. Thanks again guys!

 

[strutaeng]

Thanks for your responses. A supercharger really isn't a consideration as I'd love to keep it all motor, however a stroker kit does sound very interesting. BTR has a stroker kit for a 5.3 which I'll definitely be looking into. My 5.3 is in great shape and going the stroker route will definitely be cheaper than building a 6.0 swap where I live. Thanks again guys!

You can purchase "stock" 5.7 replacement pistons/rings and take them to your machine shop to get your block bored out. You would keep your crankshaft and rods (they share the same stroke), but just get the rotating assembly rebalanced since they are different bob weights. Everything else you reuse. Your cam should work nicely with that displacement. Basically a 5.7 LS iron block.

If you want a stroker, then you will, in addition, replace the rods and crankshaft. Either 4.0" or even 3.90" stroke. It really depends what you want and what your budget is. There's tons of options out there for these engines.

Check this out: https://www.enginelabs.com/engine-t...dget-iron-block-5-7l-ls-from-a-scrapped-5-3l/

Note they said they didn't have to rebalance the rotating assembly. I would get the machine shop to check that and they'll tell you.

 

[justirv]

Thanks for your responses. A supercharger really isn't a consideration as I'd love to keep it all motor, however a stroker kit does sound very interesting. BTR has a stroker kit for a 5.3 which I'll definitely be looking into. My 5.3 is in great shape and going the stroker route will definitely be cheaper than building a 6.0 swap where I live. Thanks again guys!

Recommend sonic testing your block to see how far out you can go, most/all can go to 3.900, some to 3.902, and a few even 3.903. Have fun!