Cam selection help

I think if gear braking and stock convertor are needed, I'd go with a steeper rear axle ratio. Somethign like a 4.10:1. I haven't raced SOLO but a buddy's father was a tech inspector for SCCA for years and in the past had some insight. You are on and off the power a lot and almost never in high rpms. You're better having some gear not only to pull harder low down but also to maintain the rpm range in middle gears.
I'd also go with a solid flat tappet stictly for torque and midrange. Either the 270S or XS268S Comps.
The FL lobes are a great lobe and I've used them a few times in stroked applications where you have the head/port for it. But in terms of low and midrange with a basically stock port, weak exhaust port, and long rod - I think the Max Area low lift lobes might be a better choice. The cam can be ground with less overlap and even though they are a faster rate of lift, they are a little "later" in terms of when they reach max lift. That puts the piston in a better spot to pull harder during the max lift. Just a thought anyway...