If I use just change out the inner valve spring on my R to Portflows, and use Toda B's; will that be enough security to avoid any valve float or anything else damaging to the engine? What would be my max RPM with these inner springs?

 

https://honda-tech.com/zerothread?id=71600

search.... you might get a lot of that here...... good luck.....

 

If your using your stock ITR Exhaust outer valve springs (blues), the maximum lift they can handle is 11.5mm, any more and they will coil bind. If you up grade your exhaust outer valve springs to the stock ITR intake (Yellow) you can handle up to 12.5mm lift all around. HTH

 

From what I understand, spec B and spec C TODA camshafts require TODA valve springs.

ITR outer/inner valvesprings may be used up to 8400 RPM.