will this work?

will this cam fit into 1970 225 http://www.summitracing.com/parts/CCA-K64-246-4/ . the engine dident have hydraulic lifters before but this cam kit will add them.

No, this kit won't "add them", it's for later hydraulic lifter slant sixes. The earlier, solid lifter engines are oiled differently than the later hydraulic engines. I think the older solid lifter engines can be converted to hydraulic(and vice-versa), but why? Just get the correct solid lifter kit and adjust the valves a couple of times a year.

I've never heard that many positive reviews for Comp Cams for the slant, unless it was a stock-type rebuild. If you want to improve performance, there are better choices.