JJones126 Posted August 11, 2011 Report Share Posted August 11, 2011 (edited) I just came across some ls3/892 heads. Is there a benifit to swapping these onto a LQ9 engine? Qurious what some of you gurus might think thanks. Edited August 11, 2011 by StillwaterSS (see edit history) Quote Link to comment Share on other sites More sharing options...
The_aSSet Posted August 11, 2011 Report Share Posted August 11, 2011 I think u had a typo l92 heads. And are they ls3 or l92, ls3 has different valves I thought. But to answer your question yes, they flow sooo much better than our stock heads, do u have a cam? Also you would need a l92 or ls3 intake manifold to run these square port heads Quote Link to comment Share on other sites More sharing options...
JJones126 Posted August 11, 2011 Author Report Share Posted August 11, 2011 (edited) 892 is the casting #. No i'm bone stock other than a CAI kit. I was thinkin they might be worth havin around for future mods. From my understanding they are the same heads (LS3/L92) Edited August 11, 2011 by StillwaterSS (see edit history) Quote Link to comment Share on other sites More sharing options...
detjoe Posted August 11, 2011 Report Share Posted August 11, 2011 (edited) they are worth it if you get them cheaper than from GM and they are complete....AND b/c they are in decent demand so you could sell the pretty easy (BUY cheap ) and if thats the casting # for the nice valves more reason My L92 build was budgeted to be cheaper than a radix. I felt I could get a similar ET and be at a better starting point for some boost. Edited August 11, 2011 by detjoe (see edit history) Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 11, 2011 Report Share Posted August 11, 2011 892 is the casting #. No i'm bone stock other than a CAI kit. I was thinkin they might be worth havin around for future mods. From my understanding they are the same heads (LS3/L92) 892 isn't a L92 or LS3 head casting number... the 823 heads are L92 and 821 is the LS3...the casting is the same but the LS3 has the lighter valves... look at the intake valve and see if it has a very smooth maching face if it does it is the lighter valve... the heavier valves look like it is sandblasted.... or very fine sand paper. Quote Link to comment Share on other sites More sharing options...
JJones126 Posted August 11, 2011 Author Report Share Posted August 11, 2011 892 isn't a L92 or LS3 head casting number... the 823 heads are L92 and 821 is the LS3...the casting is the same but the LS3 has the lighter valves... look at the intake valve and see if it has a very smooth maching face if it does it is the lighter valve... the heavier valves look like it is sandblasted.... or very fine sand paper. You are correct they are 823 heads and yes the valves look rough. they are l92 heads. Are they still worth lookin into, i suppose i could put in LS3 valves then. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted August 12, 2011 Report Share Posted August 12, 2011 I'm still on the fence about the l92 heads on our motors. They do offer a very good upgraded flow rate, and the ability to run a 90mm tb. However, the cam shaft has to be spot on to work. It seems the cam selection will make or break the set up were as the cathedral port heads seem to be pretty forgiving. The compression ratio will be the same so thats a wash. I've read a bunch of dyno tests and they always seem to come out on top, but in the real world i just don't see the set ups really beating the cathedral port stuff. I guess if i had to choose, I'd still go with the catherdal port heads. Trick flow 225 if the budget allows, ls6 next, and then 5.3 heads or our stock 317 heads decked depending on the set up and compression desired. Quote Link to comment Share on other sites More sharing options...
detjoe Posted August 12, 2011 Report Share Posted August 12, 2011 Brad, I wish you could feel my truck to get a good comparison....cam research almost killed me. I ended up pretty mild, only thing I would have liked was to get the lift into the .600" where the head really flows, but when I did my swap there were not as many running set-ups to get PTV measurements. Now guys are running more cam with my same set up and less worry about kissing a valve. Quote Link to comment Share on other sites More sharing options...
The_aSSet Posted August 12, 2011 Report Share Posted August 12, 2011 (edited) Detjoe im pretty much about to be running your setup and I did all my research and came up with the same answers as you and THEN I found your thread and I was suprised how close we were with our selections. I got my l92 heads for $300 so I couldn't pass them up, and in fact I have 3 heads so ones going to ebay since its damaged in one cylinder. Edited August 12, 2011 by The_aSSet (see edit history) Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted August 12, 2011 Report Share Posted August 12, 2011 (edited) joe please don't take that wrong, I'm in no way saying your set up is bad or will not work. Like i said they seem to be beating everything in all the research i do, but maybe just not enough guys are running them in our trucks yet, so i can't see the results I'm looking for. They are a cheaper option to just bolt on more flow compared to getting a set of ported heads but I'm just stuck on the cathedral port heads right now. I guess for the time being you could say i'm being a little hard headed about it. Edited August 12, 2011 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
detjoe Posted August 12, 2011 Report Share Posted August 12, 2011 I did not think that at all, I know you have a 'thing' with those cathedral's I got too good a deal on alot of my swap parts so that pushed me to the GEN4 stuff. Quote Link to comment Share on other sites More sharing options...
zippy Posted August 14, 2011 Report Share Posted August 14, 2011 I would certainly go for those heads. If you can get them at a reasonable price they will offer a very nice performance gain even with the stock cam. Keep in mind that you will need to change the intake manifold also. Down the road you'll really want to make sure camshaft choice reflects the heads you've bought though. Quote Link to comment Share on other sites More sharing options...
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