What is the best tool to remove the springs with the heads on? I have this one already and it just slips right off. It might have a bad spring but is there any ones where I can just screw a bolt into the rocker?
https://www.autozone.com/test-scan-a...***/231210_0_0

 

I've used that style before on mopar engines - but not that brand. I haven't tried it on a magnum head. The stock stem seals on the old 383s and 440s were usually trash when I got them. You are saying it isn't hooking onto the loop of the spring?

You'll want to make sure the valve doesn't drop into the cylinder. I used a fitting in place of the spark plug to pressurize the cylinder and keep the valve in place (with an air compressor).

Semi poor life hack, use a large deep well socket and smack it down once with a hammer. The keepers generally pop out so you want to put rags around where you are working so you don't loose them. On occasion they get jammed in there, so you have to do it again. Just don't hit the valve stem by accident. SummitRacing has something similar done as a tool:




And there there is Lisle's product:

 

That tool actually works fairly well, but, does require a certain technique to make it behave. Grab the spring as low as you can, but, NOT all the way to the bottom. Put it where the 'tongs' get get a grip around the spring, and kinda hold them on there while you tighten it down. Be warned though, if the spring slips out once the locks/retainer is removed, you will never see it again.

Be sure and have some method of preventing the valve from dropping into the cylinder as well, either air pressure, or, put some rope into the cylinder (cotton rope please, not nylon), and run the piston up against it, and that will hold the valve in place.

 

I was near the toolbox, so here is the tool I bought years ago. This one worked nice for me, on a few engines.

 

I have an air compressor, its just when I use that one all it want to do is slip off. I had to ziptie the base together for it to not fall off the spring.

 

Maybe get a better version of it, like the one pictured in fj5gtx's post. That looks EXACTLY like the one I use.