Just got off the phone with Doug from PDW. I went with the 4.5's. Doug was very helpful. They are about 3 weeks out as Don is pretty busy right now. So in 3-4 weeks I should be pulling the DD-3's and installing the 4.5's! I expect the difference between the old extrude honed DD-3's and Mach's to be pretty big. I can't wait to get them in. There is a dyno event on March 21st, and if everything goes well I should have them in before that.

 

Congrats! on the injector purchase. I love mine.

 

whats the difference between the 4's and the 4.5's?

 

About 25HP.

 

Any performance difs?

 

The dif between DD-3's and Mach 4.5's should be quite noticable.

 

are the DDs that inferior to the machs

 

DD-3 = extrude honed, ~110 Hp
Mach 4.5 = EDM technology, ~175 Hp