Thanks for the info. I was going to stick with the 1.5 to keep from trimming the valve guides and messing with screw in studs, but 1.6 are still a possibility. I have flat top pistons and going with an arp stud kit for the heads and mains. I'll have to check out the .016 head gasket, cometic maybe? What about a double row timing chain set? I know slight strength advantage and but slightly more rotating mass, but seems to be a debate as to whether it will fit or not. I know I'll need an aftermarket cover with a crank sensor hole.
Use the comp 787 retainers and the LS6 springs, no need to cut the guides. I have had the LT F-car cam and 1.6s on stock springs and retainers. I had .0530" retainer to valve seal clearance on multiple sets of Vortecs simply fully seating the seals. Ran them thousands of miles with no ill effects too.
Felpro .016 rubber gasket has worked well for me. Current setup has the GM 0.028" MLS gasket because I have aluminum heads on it.
I run the GMPP single roller chain on my 350 with .578" lift on a 215/224 @ .050 comp custom grind cam and double springs. Has not given me issues with the occasional 6,200+ rpm shift and 6,000 rpm shifts everytime it is driven. I also run a big block oil pump. My CMR has not changed at all in 20K miles. I datalog the CMR angle everytime I change up the tune on mine. It stays a consistant 0.2 to 0* every run even at WOT high rpm. I do have an aluminum base distributer for cam signal reference only and it is correctly shimmed. I have not had the engine cover off mine in 8 months and about 20K. Since the engine has been together I have changed the oil once, the engine filter 4x and cleaned the K&N once. I run an Amsoil bypass filter. The oil looks like new at 10K, Blackstone testing shows it could go 20K but Mobil One 0w40 is fairly cheap. My bypass filter gets changed yearly and its not cheap but it is worth having like new oil forever in the engine. I think alot of the good oil testing results are the Total Seal gapless street rings that keep blowby to an absolute minimum.