Originally Posted by DeweysHeads

The 106 will be right at the spot where with flatops and that cam the CR will be close to optimized. CCing the heads would be smart to get them equalized but that can be done without milling assuming they are close, or mill one slightly to bring them to equal, depends on the volume they measure what to do.
If doing headwork sure go for the 1.9" valve and don't scrimp there. The HP I mention will not come without added airflow potential (verified by flow testing on a bench) and the valves help that but I use a stock exhaust size both are premium AV&V parts.
The TB will not be of any help without the headwork. These parts work together and always the assumption is the pipe and tune are good.