This is not a Dinan bore it is better. Big Bore throttle body. Custom bore to biggest bore size that can be done, custom brass butterflies. The 318 TB has two bores one small bore for daily driving and the second Big Bore opens up for maximum air flow. This TB has a welded pipe from 5 1/2" down to 3". The pipe can be cut off or you can use a 3" to 2.5" adapter hose or convert to 3" piping
This TB has only the Big Bore machined to the largest bore without compromising the TB's strength. It is slightly bigger then a Dinan bore. Works perfect during daily driving and allows additional airflow through the larger bore for added HP.
$300 to your door lower 48.
Picture one is of the bore and picture 2 is what it looks like on my car.
Big Bore Throttle Body (Dinan) 
Linear Mode
