Valve spring compressor

I thought about this design but I wanted something to replace valve springs with the heads on. I have to run a lighter spring during break in then change them after I dont want to pop the heads off just to change springs

That’s a great point that I hadn’t thought of. I made the tool out of necessity during a complete rebuild, so the heads were already off. Looks like I’ll be following your design in the future if the opportunity presents itself!