Truth be told, I wouldn't have wasted the money on either injector upgrade right off the hop. The stock 19's, a larger fuel pump and an adjust able FPR would carry you thorough pretty much any bolt on set up until one chose to step up to a serious H/C/I top end.
....which is exactly why I waited till I bought that top end in order to upgrade those components. No need for a tune, and no real loss in horsepower to speak of. At least nothing that showed up on the all important SOTP meter.
And yes, I did go with the GT40X's....which I'm quite aware is a "middle of the road" head as far as what is available on the market today. I'm also quite aware that fore another $500-$700 over what I paid, I could have picked up a set of used TFS, or AFR's and been further ahead in the power department....but then I would have been behind schedule on my build and wouldn't have been able to afford, or coordinate it with the delivery and build of my stroker short block to go along with it. I had another roller 302 block here, so it seemed to make more sense to me to built the engine on the stand and drop it in place as a single unit over a weekend with minimal down time that to wait till I had it out of the car to start my build up.
BTW....I've spent nothing on tuning with the set up (although I'm not against it....more because I just can't leave stuff well enough alone, rather than out of necessity). The Pro-M 80 MAF meter and 30/lb/hr injectors for the most part seem to be working well together. I'm pretty certain my drivability issues experienced last season revolved around the bad head gasket I discovered in the fall and hope to remedy this spring.
Had I done it the other way, I would have had to pull the engine (or at the very least lifted it) in order to fit the long tube headers I had, and surely maxed the 19's with the TFS head's, intake and supporting parts....requiring the fuel and intake component upgrade right off the hop. That is of course until I needed to tear the engine down a second time in order to send the block out for machining to install the stroker kit and camshaft that I couldn't install the first time around.
I knew I was going to be in for a compromise at some point in my project. It just seemed simplest and the least amount of hassle for me to choose the heads as the choke point, that could be changed in car, in a matter of hours over anything else. The other way would have had me down for weeks, with considerably more hassle and expense.
Ahhh....different circumstances altogether. Your nitrous kit pressurizes your rail, driving up the fuel pressure to feed the injector in order to fulfil your horsepower needs. Try feeding those power levels on an all motor set up and you'd have those 24's screaming for mercy. lol