yeah, i got a good deal on my L76. 300 and it came with rails/injectors. valve clearance would be only thing to worry about i would think.

 

L92's have a weak exhaust side and need more exhaust timing to take advantage of the intake flow. imo

 

Thats true but can be corrected threw a couple of different methods. More durration and/or lift on the exhaust, better exhaust system, more port work on the exhaust side just to name a few.

 

Hard to beat the L92s for hp/tq. They run very strong low end torque as a % of hp. The stock intake does seem to fall off somewhat above 6200 but it so nicely balanced, why worry? The only issue would be trying to avoid a shift on the track, IMO.
The sheet metal and carb intakes will make more hp but at the expense of tq.
Seems to be the old runner length trade off.

 

stock L92's here on a cam only 6.0 .
137.20 mph through the traps at 7K, not falling off, still pulling,
ET is signature.

 

dm what does it RW dyno?

 

Can't be run on a dynojet for tuning, will not properly load the engine for the carb I'm running. Tune for MPH at the track.

Dave

 

DM what cam specs you running and who'd you get the cam from? guessing 4k stall and 4.11 gears?

 

nevermind just searched for you thread on it. nice combo. how much did the flycutting cost you to get done?

 

I clayed the pistons with no headgaskets so the machinist could set up the pistons for cutting. Disassembled the shortblock and took pistons to the shop.
Only needed to do the intakes, cost 180 bucks.

Dave

 

Definately flow check whatever you decide. $900 for a pair of heads is only good if they flow as advertised & everything checks out at the machine shop.

 

You guys are listing these outrageous flow numbers, but at the track and dyno the AFR, ETP and Trick flow headed cars are stomping the **** out of the l92 cars in most cases, and their flow numbers are alot less than the L92 numbers posted here. Is it because of the intake? Everyone is touting these heads but I don't see it in the real world. I know that there are a few L92 head cars that are making big power, but i think the heads are worked to the *****. Out of the box, from my research, the AFR, ETP and TFS are a better performing head in the real world; of course they are about a grand more, but that still doesn't explain the flow numbers. 320 for an AFR Vs. 360ish. C'mon.

 

First off...
What do you already have?
Do you have a LS1, LS6, or Fast manifold, maybe even a Weiand Aluminum LS6, or a Typhoon Aluminum...
What injectors do you have 24 # hr, 32's, 39's, 45's, 42 green tops?
What is the combustion chamber size in your current heads?
Do you already have a good cam for the Cathedral heads or are you running a stock cam currently?
Throttle Body are you currently using a stock 76mm, ported 76mm, aftermarket 90mm?

Patriot lists on there site that the Chamber size for the LQ9's at 72cc.
The L92 heads are 70cc chambers stock and some of the ported ones have a 73 or 74cc chamber.
If your current head is a 64cc then you will loose some compression.

Essentially take a look at what you have and compare it to what you will need. Combine that with what you have to spend total and figure out what is best for your budget.