lt1 head Cast vs Al?

[ls1 nova]

Anybody have any opinions. Tried to do some searching and didn't come up with much. Heard the iron may flow a little better?

[Pro Stock]

I would go with the aluminum castings, the first place to start looking would be Summit Racing, look for "Trick Flow Lt1 heads"

Dale

[camrat68]

As long as both sets of heads are STOCK and completely unmodified, the cast irons out flow the alum heads on LT1's. However, porting cast iron is a LOT harder on tooling than porting aluminum so I guess that we'll never know whether ported cast is better than ported aluminum. One thing to keep in mind though is that cast heads are straight plug where the alum heads are angle plug meaning your headers may no longer fit as I found out on my buddies Caprice.
Just my opinion, the Trick Flows are a nice piece, but I think they flow a little too much for a 350 or 383. Maybe once that new Dart LT1 block comes out the Trick Flows will really be able to shine. Me, I went with ported alum GM castings.

[Pro Stock]

This is a new product that looks really good to me, high flow numbers are a good thing, volume and cross section have to be matched to a given engine size and intended use. Out of the box these heads will out flow the stock iron heads and should work well on a 350 to 400 ci engine, if you are going to turn the engine relatively high rpm they could stand to be about 15 cc larger, most of that volume should be made up in the bowl area. I've been building high performance and race heads (mostly Pro Stock) for over 30 years, hope this helps.

Dale






AKRON, OH. Trick Flow Specialties introduces the best-flowing cast cylinder heads available for naturally aspirated LT1 engines: Trick Flow GenX™ Street/Strip Cylinder Heads. Out-of-the-box, these heads are easily capable of producing well in excess of 500 naturally aspirated horsepower.
The GenX Street/Strip Cylinder Heads for GM LT1 feature 54cc combustion chambers to maintain the factory 10.25:1 compression ratio, but have CNC-profiled and bowl-blended combustion chambers to maximize performance.
The heads have 21° valve angles—reduced from 23°—to increase piston-to-valve clearance and unshroud the chambers for better flow.
GenX Street/Strip Cylinder Heads for GM LT1 also feature 185cc intake and 67cc exhaust Fast As Cast™ runners that duplicate the port shape and profile of fully CNC-ported runners. The result is near CNC-ported power and performance for the same price as standard cast cylinder heads—and the best-flowing cast LT1 heads available.

The fully assembled heads come with stainless steel 2.020" intake / 1.600" exhaust valves, GM LS-style 1.300" double valve springs, chromemoly steel retainers and locks, guideplates, and ARP 3/8" rocker studs. In addition, these heads retain the use of all stock sensors and fittings. Bare cylinder head castings are also available.

Airflow data from SuperFlow SF-600 flowbench:

Lift: Int: Exh:
.100 65 54
.200 138 117
.300 202 162
.400 243 189
.500 270 197
.600 273 209

Flowtested on 4.030" bore @ 28"