I am still waiting on vararam to finally finish their new crossram intake that should net great results with our ls3 engines. The fast 102 was made specifically for a built engine in a given rpm range more over requiring a larger 102 mm throttle body that a ls3 would not need until it is way up the food chain in power. I run a vmax and am at 550 flywheel hp and plan to not do my heads unless its a total rebuild as our heads flow great according to top builders up to and even over 600 hp, the runners vararam is building into their intake are able to be varied in length and much longer giving a car the more tunnel ram effect from being cross ram and I believe going to be one of the best new mods to come out for our engines. And they are stating up to and over 50 h.p. and 50 ft lbs to 60/60. I do not know what effect having such a aggressive cam as what I have will have with this intake but I am betting it will bump me to around 600 and cannot wait to try one. I will not do my heads as the cam I have surely would have make my pistons be flycut or worse cause other issues and I have 112 LSA which is close as is.
The tuner I used uses h.p. software and is the best in my area, I have heard many posts on other sites of tuners who are not so great, people buying cams and going off a name, or not researching things well and being disappointed in various products.
Though this may not be the biggest of forums we could have told you to expect very little results from the intake as it is meant not for just a stock or mildly modded engine. If I were you I would consider keeping it and waiting if your going to go to bigger and better things with the rest of your build, or selling it and waiting, or finding another tuner if yours is not the most competent as I went to a g.m. guru...not just some speed shop that does every car to tune mine.
2013 2ss/rs NPP CRT, Forged 428 ls3 stroker, Mast windage, GMPP ported heads, Katech chain, Trunnion upgrade, Cam motion stage 3, SP headers, Vmax PTB, Monster c7 dual clutch, Mgw shifter, Fluidampr 25%UDP, CAI induction, rocket racing wheels, clutch reservoir, bmr toes and trailing arms, Lpw diff cover , scanner, drl's led /fogs, elite catch can, MRT louvers, tint, ZL1 spoiler, stripes & badging, etc....