I am really considering some Stage II Patriot Performance heads. How much rwhp can I expect out of these babies?

 

I'd also like to know this.

 

Thats all going to depend on your specific setup, including cam and exhaust mods. For a 5.3 motor, I'd choose a 5.3 head to keep decent compression. You should probably talk to them about getting a custom head, not just their stage1 or stage2. The stage2s have 2.02 1.57 valves, which might be too large for the small bore of the 5.3. Physically the 2.02 may fit, but flow may be restricted. Ask about a stage2 with 2.00 intake valves. See that they way about the exhaust valve too.

 

just to give you an idea, i think i recall an f-body guy w/ stock internals and a TR224 and bolt ons, pick up 30+rwhp with the stage 2 patriot 5.3 heads. so maybe you'd pick up something around there, even tho alot of things would be different when you come down to compression, air flow and such of your 5.3 to his 5.7.
i'd go for it if you have the cash, would probably work well w/ your cam and bolt ons,
oh and cup holder

 

Heads don't seem to get a whole bunch in peak power like a cam only swap does BUT you usually gain more power throughout the rpm range if your cam and heads are matched up correctly so even a 20-25hp gain can mean a lot in ET. This is generally how it works on F-bodies but since we start off with better heads I am not 100% on the trucks. I know ALOT of F-bods that have heads/cam and only put out 280-400rwhp and i know cam only guys that put out the exact same. The ones that shine are the ones that are truely matched and tuned and MAYBE see 420+rwhp but around my parts that is kinda rare. Makes me wonder where all these guys online are dynoing at OR what they are not telling everyone.

 

Thanks guys. These is my cam and exhuast
comp cam 218/218 522/529 114
ASM headers single 3" with no cat

In a nutshell, you all suggest my best bet would be to just buys some used 4.8/5.3 and have those custom made?

 

F8LPONY, our truck heads arent better than LS1 heads. Our heads flow less stock than them. The reason 5.3 heads do so well on LS1s is they have smaller cc chambers, and increase compression without milling, and retain valve clearence for alot of lift.

I had my heads milled .050 and ported as one of my first mods. With just the head work, and some minor intake work it felt like a whole different truck. Call me crazy, but id say i easily saw @ 40 more rwhp. It had way better low end, and crazy top end.

If you get the stage 2 heads, id go with the ones with small chambers and 2.00 intake valves. You dont want to drop your compression in the swap. If anything, bring it up a little. If your going the boost rout get bigger chambers and drop the compression.

 

SnakeEater, you are correct bro. I meant "we" as as in fellow F-body owners because I still own my 00' T/A It just doesn't run low 11s anymore

From an expense perspective heads are a pretty crappy return IMO. Although now that heads are getting cheaper for basic porting it is starting to look a lil better but back when I did my first heads/cam on the T/A you could easily spend $4500 with parts and labor and only end up with 380-400rwhp. That's pretty crappy IMO.

A typical bolt-on heads/cam 5.3L probably wont make much more than 340rwhp I would think (san dyno tricks).

 

oops, sorry. I miss read, but it makes sence now.

When i bought the Z28 back in Sept. the same lot had a 2001 pewter WS6. Ive been regreting not getting it every since then. I like the styling and interior more in the T/As. Thought about a Firehawk hood?

 

what if u put some ls6 heads on a truck. What would they do.