Cam and Stall Convertor
I must have missed something because this is a race car...
Put a 4000-4500 converter in it with a thumpr or voodoo with springs or a solid with rockers/pushrods and springs and you're looking at less cost with hyd.
Spend 300 on a junk converter now only to buy a better one later for more money. Works out same in the end sending the 8" back for a re-tool. Most vendors will do it at least once for free so no $'s out there except shipping.
This is a patchwork build with the desire for more power. pick your poison. I'll take the bigger cam with a bunch more converter, it's a race only car, which will DEFINITELY cover the lack of 4 series gear. Not like it has 2.76 gears in it, it's got 3.91's and short tires. If this was a street driven, daily driver, no way in hell would I suggest anything like that.
Heck go grab Strokers favorite reading material, the chassis manual and see what they say about getting a 318 into the 12's... :)