I'm a believer in Valvoline Conventional, thats what I run in my GPs and my family has used it for many many years with many vehicles hitting the 500k mark without issues.
I use Mobil1 in my TB SS since GM factory filled those with that stuff (LS2). Figure it wouldn't be a good idea to switch since its had it all of its life before me. This is the ONLY reason I used it. Since its not a DD, it generally gets regular 4 month oil changes like clockwork.
I'm also a believer in 3k or 4 month oil changes religiously. Thats how i've done it and that how i'll always do it. I'm old fashion, I think oil should be changed regularly and thats how I roll. Its worked for us for many years.......
