They are both good. I have an eagle 330" kit in my ranger. Now that I have a better cam in it, it moves so nice.
I can't say the Eagle has been without issue. The first kit had the wrong crank (347). Since then I have heard of this happening more then once (both brands). Eagle customer service was top notch, paid shipping both ways, took care of a piston problem I had (ring land dinged and only 9 pistons left in the country) that probably wasn't even Eagle's fault, KB. The balance is perfect. all the parts fit right.
But they did have one little warning burried on one page that bit me. The pilot bore on the back of the crank isn't machined as deep as OEM for some reason.
Would I use Eagle again, yes.I have been dealing with parts like this for a long time. The customer service is top rate and the overall product is very good.
When researching it I made a trip to SEMA and talked to the reps in person, twice.
Now if I wanted a custom one off part, then I would do Scat. They will build anything for the money.