Which valve springs?
 

I have a Comp Cams 156-401-13 and I’m working on getting everything else I need to go with it. It’s going in a 2008 L92 6.2L. Summit’s web site shows the PAC 1215 and 1218 as compatible but one is shorter than the other so I don’t know which to go with? Comp’s web site only shows their options which are twice the price. Also, are the beehives good and reliable springs? I’ve cammed two other vehicles and I used the double springs on those but I feel like those are overkill for this cam.

I'd go with the 1218 if it was mine.

LSx Beehive PAC 1218 Racing Valve Springs | WS6store.com

They have a kit also I think, with retainers etc. if you want the whole deal. Might have to call or email them.

Is it a good idea to replace the retainers and stuff? I was hoping I wouldn’t have to going with the beehive springs but I’m not trying to cut corners either. I am trying to keep this as cheap as possible but not at the expense of reliability. I don’t want to have to worry about anything on a road trip. I’m also going back and forth on doing the trunnion upgrade since this isn’t a huge crazy cam but it is extra insurance.

It's not necessary to replace them.

Not "necessary", the stock ones will "fit", but if it was me, I would.

The PAC kit with the 1218 spring is the KS14 and I’m seeing them for $285 so if I’m going to spend that much why not spend $15 more and get the BTR dual springs with everything and titanium retainers? The chromoly steel retainers kit is only $230.

Might as well do it right the first time

The beehive is lighter than the duals which give them the advantage of less valvetrain fatigue at higher RPM's . The duals give you the piece of mind that if the outer brakes the inner may save the engine from dropping a valve. Another disadvantage besides weight with the duals is the unnecessary spring pressure by jumping up to a .660 spring on a sub .600 lift cam. It's harder on the lobes and causes more parasitic drag than necessary on a .5xx lift cam. I've read where the PSI beehives have no reported spring breakage but they are more expensive than the PAC' beehives.

PSI Beehive 1511ML

Unnecessary spring pressure is why I was originally going to use the beehives. I thought beehives were designed to be drop in replacements and not need the retainers and all replaced (although I was considering doing new GM valve stem seals) so when someone says they’ll “fit” like its going to fail I was thinking I’ll buy what I know won’t fail because I’ve used the dual springs in the past.

Yeah it's tough sometimes balancing risk vs $$$... there's no hard yes/no answer for that question in lots of cases. Replacing the retainers falls into that class of things. The PAC ones look very slightly lighter than stock, at least the ones I had to compare them to, but that could be an optical delusion. I didn't weigh them. Lighter would be better of course, and not worn better than worn, but replacing them doesn't seem to be mandatory.