Well...I "chickened" out...so to speak. More of a "what can I trully do today to meet my goal" actually, the goal being: fire up the motor before the season is completely done (southern Ontario here, think Detroit, MI - as that is literally just across the river from Windsor).

Anyways, I decided to stay with what I currently have, that being the Manley Severe-Duty intakes. The 2.05 and 2.08 stuff is the Race series, and I just didn't have the comfort (nor readily available stock) to take the plunge.

Alright, so where are things right now?

Well, the shop did the multi-angle valve job and valve backcut, the numbers in the low to mid range improved anywhere between 9 to 15 cfm, but the high-lift stuff gave up a bit 305 => 291 @.650.

So here are the NEW numbers:

LIFT - INTAKE - EXHAUST - E_TO_I_%

0.050 - 039 - 032 - 82
0.100 - 066 - 055 - 83
0.150 - 100 - 089 - 89
0.200 - 132 - 111 - 84
0.250 - 165 - 137 - 83
0.300 - 192 - 157 - 82
0.350 - 217 - 173 - 80
0.400 - 244 - 186 - 76
0.450 - 267 - 192 - 72
0.500 - 277 - 197 - 71
0.550 - 291 - 200 - 69
0.600 - 294 - 200 - 68
0.650 - 291 - 200 - 69
0.700 - 288 - 200 - 69

I've attached a visual chart comparing a stock W2 long-valve head (MM Dulcich article since those were done on a SF-600 bench, which is what this shop uses as well) to the DIY1 porting results, followed by the valve job. Tossed in there are my old factory '596 castings as well, which were flowed by the same guy on the same bench.

Looking for some suggestions guys as to what else to focus on to unlock a bit more of that low-mid lift flow.

I haven't touched the short-side for obvious reasons, even the MP templates still show it excessively high with a very pronouned casting bump/ridge in the floor. I think I should remove that.

Beyond that, I could raise the roof a bit as per the templates, not much, but looks to be about 0.100" that could come out. The materials seems to be there to do this, but I was worried about cutting through to the head bolt passage.

Otherwise removing some material from around the guide humps is just about the only area left on the intake side.

In the exhaust port on the other hand, can I flatten the bump in the roof that's right above the guide? Seems like that could go because to each side is a lower placed (as-cast) channel, so I'm assuming the extra material there is meant to better support the valve?

I've added a picture of the exhaust ports showing that roof bump.

On the very same note, the flow guy suggested that I could square the roof on the exhaust port, basically gasket match to the TTI header gasket (which is what the square looking outline is from). Is this worth pursuing?