jeff, i am not sure that it pays to have your creampuff with nos injected this way. unless you plan on putting forged pistons in this block along with the crank, the max horsepower i have seen shot into a creampuff would be 125 shot maybe 150 but risky on the latter. the best benefit i see of using this direct port injection into the manifold is the safety aspect of each cylinder getting equal amounts of nos and fuel. on a small shot like the max a creampuff can handle why spend a grand or more to have your manifold drilled and tapped this way. now i would tell you that if you were going to change the internals to forged pieces like the earlier gen2's and wanted to run a 300 shot system then absolutly its the best way to go. ask carrot, i believe he is running a gorgeous direct port injection system like this from nitrous express. the finest kit money can buy in my opinion!-josh
otherwise just tap the smooth tubes and inject the modestly small 125. but get to a dyno to watch the air/fuel to make sure the car is rich enough for the juice. 10-10.5 is awesome and safe on the bottle. above 10.5 and your ponies will go up but so will that expensive v10! i run an apexi-afc used on many imports to dial the fuel lean OFF the juice for street driving and max HP, and at the track run it rich for the juice! my next step on my system will be slicks,skinnies, half-shafts, and linelocks to heat those babies up. watch out boys i feel low 10's on the 150 shot very soon. bump up the jets to 300 add a little fuel system into the mix and 9's all day long. how that for a few grand!!! most vipers spend 40 grand to see those numbers. Jeff, you should know, i watch that DLM monster you had run its englishtown 9.9 pass sideways through those traps. talk about dirty underwear.
Tom Welch would be your go-to guy for this one. I would say with some dyno tuning, 150 is cake; above that and you should be real careful about how much and how hard you're spraying a creampuff.
V10 is just about right on with the A/F mix, although a lot of the DLM dyno sheets I've seen run the car around 11.0 all the way up the rev-band. Something to consider, although Welch would be able to set you right.