What do you think you will want to do down the road? If you will be happy with 5.90 1/8th ets, then i would take a hard look at what it would take to get there with the 270s. You might have to get some weight off the car, but i suspect it might be doable. If you want to go faster and faster, look to a bigger head that can be opened up further. A frank talk with some seasoned dyno operaters/ engine builders will shed light on cost, versus power and reliability. In my case i expect to go 8.40s in the 1/4 at 2880 lbs but i am spending a bundle to do it. If i had put half the money i have spent on this quest in a much lighter car
I could build a much lower stress powerplant.