Wanted to get opinion about 5.3 heads, I was told that with some valve work they would make a good bit more horsepower then stock LS1 heads, have anyone exprience this or know somebody who has?

 

???

 

not really. know two ppl who put on 5.3s and lost power.

If your going with new heads get some 243s

 

As I remember, the original reason the 5.3's were an advantage was the ability to reshape the chamber. I think many better options out there now.

 

Thanks for info, but what is 243's

 

Found on LS6's and LS2's

 

Valve work and ported out to 220cc for an intake volume and they flow great!

 

Nice writeup of some 5.3 heads used to make 400rwhp: http://forums.corvetteforum.com/c5-t...-tsp-224r.html

 

I have a set i've been thinking about having work done on, about how much would you say i would be out of if i was to have the port and valve work done?

 

Check this: http://forums.corvetteforum.com/c5-p...l-springs.html

 

i used the 5.3 heads, did full port and polish, bigger valves, and milled them to 11.5:1 compression....

absolutley love the results...403rwhp with stock intake manifold. I just added a Vararam and LS2 intake and TB....can't wait to see the new numbers

good luck

 

Patriot makes a great bang for your buck CNC Ported 5.3 Cylinder Head. One of the benefits of this head is that it comes with a 63cc chamber in stock form (unmilled) which will increase your compression to 10.75.

Patriot Performance CNC Ported 5.3 2.02"/1.57" 63cc Heads Assembled $1175

Seth

 

Actually, stock chamber size is 61cc....but because the first thing to usually get tossed are the stock 1.89" intake valves...when the 2.02's go in, the chambers are usually worked/enlarged a bit to allow the larger valves to work. And because of that, ported examples typically end up in the 63-64cc ballpark.

The two notable places that really know how to turn 5.3 heads into outstanding performance heads, were Absolute Speed (no longer around), and TEA (Total Engine Airflow). There are other great head porters out there, but when it comes to 5.3 heads specifically, these two never go unmentioned.

I am running 5.3 heads on my car. They are the stage 2 version by TEA. 2.02/1.55" valves, killer valve job (and blended into chamber), milled .025" to 59cc, excellent portwork, spring heights shimmed and set proper for my cam, every edge and coolant hole deburred...they arrived to me a work of art.

And they flow pretty well too.




I was actually surprised how comparable they were to the flowchart of a new set of Trickflow 215s a friend bought...and since TEA manufacturers those too, it's an apples/apples comparison....same flowbench, tested the identical way.

For stock castings, the larger-runner 243s might have a little more potential to them, but anyone who thinks 5.3's can't be made to perform are only kidding themselves.
But again, WHO does the work and perfected the ports is probably more important than what the base casting was. And when it comes to heads, the best are never the cheapest.

 

Something that was overlooked on the PRC heads from TSP that I got.