18 Degree Vs 23 Degree Heads
In this article, we will compare 18 degree vs. 23 degree SBC heads and help you decide which is best for your engine build. I would be a little skeptical to think Chad's 23 deg heads would do less--unless the 18 deg heads are properly reworked by a skilled craftsman.
A better comparison would be a 23 and a 18 degree head within the same persons hands. Standard small-block Chevy heads position the valves at a 23-degree angle to the deck. In 1989, Chevy introduced the 18-degree Bow Tie aluminum head that shifted the valve angle vertically while simultaneously raising the intake port to take advantage of this angle.
It really depends on what you're trying to do with the car but most of the time a TFS255 head is going to be superior to an LS3 cylinder head. I would keep the Trick Flows. To buy new, I would use a real 18 degree head, and buy the proper rockers and offset lifters.
That's my advice. I was wondering if 18 degree heads are worth it. If you use the same brand and everything the same, how much more power can you exspect out of a 18 degree head, compared to a 23 degree head.
While the 18 degree heads are a better head for all out racing than a traditional 23 degree head, there still are some very good 23 degree heads on the market. Most of the small block run on this site use 23 degree heads and they still do make a great street head. We have a 406 that made 705hp with 23 heads and it has had quite a bit of port work on the heads and intake, 15-1 compression on alcohol, with a pretty aggressive cam.
If the dollars are basically the same to buy a new top end, I would think the 18degree is the way to go. The angle of the exhaust manifold flange was changed from 35o degrees to 40o degrees on 18o degree heads. This revision smoothes the flow of burned gases at the junction between the ports and the primary header pipes.
Upper end 23* heads require dedicated intakes, and the flow is close to an 18* head. Both require dedicated valvetrain and intake-but the rolled angles, and straighter
