Description:

I bought these heads on September 15th, 2008. The plan is to rebuild them to bump my compression back up to 12:1 or higher as it was before I did the rebuild and was forced to reduce compression to the 10:1 range. It lost at least 100HP and I just have not been happy with the performance ever since. I hope these heads will get it back to the performance levels it had prior to the last rebuild when I was forced to ditch my TRW dome pistons for 0cc Keith Black Hyper pistons. Going from my current 6X-8 heads (with 95cc chambers) to these 670's (with 72cc chambers) should easily put me back into the 12:1 range or more. I calculate about 12.5:1 static with my current setup.

Approx 10.25 to 1 compression with 6X heads. 433HP on motor, 558HP on nitrous.
Approx 12.75 to 1 compression with 670 heads. 577HP on motor, 702HP on nitrous.

Photos:

Here is what the heads will look like after they are ported and polished:

I intend on installing 5.090 2.11/1.77 stainless Ferrea valves, Comp cams springs for .660 lift, and 1.65 aluminum roller rockers. I am also going to port and polish these to flow as best I can, and get a better set of headers to take advantage of the flow.