The 300 works very well with stock carbs. Better with bored out stock carbs, and better still with big and juicy 38's!

However, the jump from bored stock to the 38's is not as good as it sounds without some more mods to the porting. Basically the port timing and area are more aimed at use with the stock parts.

I've got a pair of cylinders in production with porting worked out for BIG carbs and higher rpm. We'll just have to see what happens.