That's all I use in my flat tappet hydraulic lifters 440+6, and what I used to use in my wife's 421. Now that the 421 has roller cam and lifters, the 3rd oil change (1st was engine builder's choice of red break in oil, 2nd fill was VR-1 10/40) is going to be regular Valvoline, and then 100% synthetic oil from that point on.
When I changed the lifters in my 440 I added Lucas break in on that fill and the next one. I will use VR-1 in my 440 until I build the stroker, which is going to have solid rollers-per the
advice of IQ52