That's a little aggravating.... 20 hp difference, no real difference in the parts that I can see. Maybe the midlength headers vs. the shorties? Here's the parts I've got: picture

 

you said you had 2 burnt plug wire... im sure that wasnt helping your numbers

 

yea, 1 or 2... you can hear it cutting out near the end of the video. I'd often wondered what difference those bad wires made; now I guess I know. Glad they're fixed now.

 

Also i have a catless exhaust 3" from Ypipe back with a dynomax muffler. I also had it dynotuned which helped out alot.

 

I'm cat-less too... flowmaster afterwards. MadZ28 tune, the dyno was done w/ the cutout open.

 

I made 330/345 with my 305 with SLP headers, no cats and 2.25" Flowmaster catback with my Impala. Got it tuned and the rev limiter moved from 6k to 7k and she really woke up. You have plenty of clearance with 1.6rr's with stock heads, just need better springs.

 

I checked where I got the kit (it's been a couple years) and it was the full hotcam kit; Hotcam, springs, retainers, and keepers.