bortous

That's better.
If you read my thread, Tony says himself the advantages of the cathedrals.
The jist of it is, you will make more torque with the cathedrals with much sharper throttle response off idle to around 4000rpm.
You will also make around 50hp less peak power too.
It's application dependant.
I went with his 245 cathedrals on my 434.

Burken01

iTrader: (88)

Exactly, if your goal power figure can be made with the smaller cathedral vs the bigger ls7 then go to the smaller. Like my 416 tony built and we nearly made 700hp with 240 cathedrals. It should be crazy responsive vs a bigger head @the same power level.

bortous

That's exactly right.
Your heads are pretty much maxed out so you are fully utilising the head.
I wonder if there would be any more power to be had with an even larger camshaft or even a solid roller upgrade.
I'm curious to your engine would do with just a camshaft upgrade.
Theoretically if they are flowing 350cfm you can make up to 700hp give or take.




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440_Stroker

Compared to my other car with 640/600 fwhp/tq this car is about the same to 60 mph but after the first shift and this car is in its power band it will walk away. The goal was 600 RWHP and this combo has done as low high 590's and as high as 630. I'm sure dyno and day depending as well as the cars it's been in. Those were C6's where mine is in an F-Body. I'm also pushing through an S60 with 3.73's so that will lose a bit of hp with the rear and the 3.73's read slightly lower than say a 3.42. I'm not chasing a number and that 600 figure was just a rough figure of where I wanted to be but also have good midrange torque, which this car does. Almost wish I had 3.42 gears again or even down to 3.23's so first could wind out further. My T56 Magnum has the stock 1-4 gears with the shorter 5th and 6th.

lawrenq

iTrader: (2)

If we're talking about heads for a daily driver on a 434 I'd recommend ported ls3 heads. Honestly what else would you need in a daily if you're not going to the track or chasing dyno slips. Even though my Chevelle isn't technically a daily, I drive it as much as possible and I'm beyond impressed with how my 434 drives with ls3 heads.
I was on the fence going back and forth between 245 cathedral and aftermarket ls7 heads and I feel that I got a good return in hp vs $ spent.

BCNUL8R

iTrader: (2)

Most people running 9's or better are going to be building the drive train at some point in time either up front or after they break stuff. I built my drive train for a mid 9 second goal at full weight first before I started on the motor mods.

The setup I mentioned that I would like to eventually have would be either lsx or after market block. With a 427 and a big gear driven procharger you will be making more power than any production block is likely to handle long term. Every last cubic inch isn't the bigger concern with boost.

440_Stroker

Nice! I have built a car front to back and wow, what a mistake. lol This time I did back to front and everything suspension wise was done before any extra power was added.

Every last cubic inch isn't the concern but it costs nothing more to get them. With an LSX block that should carry you into very fast company and well into 4 digit power numbers. We've all seen stock blocks take big power but as you elude to they are on borrowed time. I know of multiple stock internal and cam LS3's that saw 640-700 RWHP and lived for many years as DD's but both were sold full well knowing that sooner or later there would be carnage. lol

Mickyinks

Bit of a mute point the cathedral v ls7 on a larger cube engine. Both will spin the wheels when u get on it... More than enough torque either way

BCNUL8R

iTrader: (2)

When I was a kid my school bus driver was also a local bracket racing legend. One day me and another kid were arguing about a couple cars on who would win in a race and why...LOL. We were like 12 years old and really didn't know anything. The bus driver turns around and looks at me and says...when you build a car to drag race you start from the rear and work forward. I didn't really under stand at that time, but it stuck with me.

G Atsma

Any rock star needs a solid backup band.... and good roadies!

440_Stroker

Groupie's. Lol

G Atsma

Well yeah.... LOL

FCar2000TA

iTrader: (7)

So... Mamo'd AFR 245s or BTR'd TFS 245s on a 434?
- I recall a post from Tony Mamo saying that the lowered valve angle would reduce airspeed due to the sharper curve that the air has to go around.
- AFR heads can use stock rockers, TFS require roller rockers, so that adds to the cost.

DualQuadDave

iTrader: (6)

Frankenstein F110 cathedral's or new Brodix cathedrals. New tech, check them out. Improvements over the TFS/AFR which are now 10+ years old.

bortous

I'm an AFR man so I choose them.
i also recall Tony mentioning that the 13.5 degree valve angle is only an advantage if the runner is raised.
So I guess it kind of plays into what you have read too.
Both are great heads at the end of the day.

bortous

These newer 11 degree cathedrals are interesting.
I have not seen any dyno or track results with these.
Do they even work with the fast 102 intakes?

FCar2000TA

iTrader: (7)

I am a little shy of Frankenstein. One of the smartest LS guys around mentioned to me that none of the Frankenstein 243 heads that he had seen made the kind of power that their specs would corelate to. That gave me a bad taste in my mouth for them. But DAMN, 265cc from cathedrals? For $4k, they better perform better than LS7 castings.

ramairws6

iTrader: (33)

50hp less is pretty big deal in my book but thats just me. I would never be happy knowing that lol

DualQuadDave

iTrader: (6)

​​​​​Maybe JR@FED can comment. I have no personal experience w/ their 243 program, but their LS3 821 head is a killer. Also, the M311's and F710's are making power, so we'll see what the cathedral's can do. The Brodix are going to be best bang for the buck, just watch. If it's near as good as their BR7 head, it'll be amazing. JMO, the best cathedral porter out their is probably Greg Good. His stuff puts up numbers anyway you slice them.

Darth_V8r

iTrader: (4)

I am honestly rarely impressed with any ported stock casting. The F110,310, etc are their own castings. Completely different animal. Personally once I know the airflow targets I try to find the smallest port to meet the demands. In my experience they are the best all around performers. I could care less if it is shaped like a square, cathedral, or a dodecahedron