It depends on what you want for the finished product.
.050 off the head for a street engine is a lot. I prefer to take .030 for street, you start to sacrifice strength with more cut than that.
For the valve size on a 250, 1.84 will provide plenty of flow for street use and be able to really shine when pushed harder. The 1.94 valve will need some chamber work to help get the flow to work properly.
So, I am saying the 1.84 is easier and will need less work for 95% of the flow the 1.94 will give.
Bolt in lumps will be a nice addition and give another honest 10% flow. Tom
