You're at around 370hp at the crank now and it's pushing 2980lbs to 110mph... To get another 10mph out of it, and do it hauling an additional 175lbs of steel cage, you'll need about 500hp at the crank. Is it hard? Nope. But you're basically rebuilding what you have. I dont think you'll reach it by simply re-honing and dropping in a crank with ported heads. Adding a decent crank, correctly machining the block, and the heads will eat up that $5K, leaving little for the cam, lifters, springs, pushrods, carb, or the cage and convertor... It's a big step looking at the whole picture. You've got the right base to start from. But a lot has to be upgraded or replaced. I would re-gear it. the longer stroke doesnt need the gear, and the engine doesnt need the rpm.