Thread: Brodix 18 or Dart, BMF 18 Degree, any advice.

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Originally Posted by BillR70

Hello, iam getting ready to purchase a pair of 18 Degree heads for my 400 sbc. This will be a 11.5 comp motor with a solid roller cam going in my 67 chevy 2. The car went 10.90s on pump gas last year and i sold the motor to a freind. Dart, BMF, and Brodix are who iam looking at. Brodix sells a 18 degree sp and std (Spred port, Standard port) exuast, the standard port will allow me to use my exsisting header while the Brodix SP, BMF and Dart will need custom headers. Has anyone used the Brodix 18 STD, BMF or Dart 18?
If so what can i expect going to the 18 Degree heads?

I can tell you right now you will run faster with a set of 23 degree heads.
The reason is your comp. ratio will not support a cam that will turn the rpm's to be able to use these heads.
Now if you told me your 400 sbc has 14 to 1 as comp. ratio and your cams duration was a min. of 280 at .050 and .700+ lift then I would say go for it.
A good CNC'D 23 degree head will support 675+ hp NA.
Also this will require a piston change if you run the 18 degree heads.