First of all, I dont know what surface you are running on but I would get rid of the Razrs!!!
Anyway, i say stretch+wheelie bar. We run a gas 350, drag ported, 34mm lectrons, best time of a 4.42 in 300ft. We run a +4 swingarm, and metal tech 3 1/2 forard a-arms. No wheelie bar.
When I took it to the asphault with duros, I ran a 15/40, when I could make it hook( this was before a-arms and shaws), it wanted to come up. It ran 7.60s with this setup (but its got a lot more in it).
If you can get a +6 to hook on dirt, go with it and a wheelie bar, probaly a +8 if your running slicks.