Been fighting a bit of a cold lately, and felt Sunday was better spent with the girls baking and decorating cookies.
Anyway, this engine continues to fight me in one small way or another...
Started off by degreasing the sludge filled oil pan (165K miles and countless hours idling in a cop car will do that), and the front and rear covers. Then it was time to get the oil pump drive on, I left a heat gun set on high pointed at it for a while and then slid it on (melted my neoprene glove it was that hot). Then on went the oil pump centered with a SacCityCorvette Align-It tool. I used a combo of the Kent Moore and SacCityCorvette tools to get the oil pan, and front and rear covers installed - all with new gaskets and seals. Popped on the LS6 valley cover - which went on really easy given this engine is based on an LS6 block. Next the BTR SLR lifters went in with new LS2 lifter trays and bolts, I had to polish one of them up with some 2000 grit sandpaper to get it into the lifter bore - no big deal.
The fun really began when I went to put the heads on and the 11mm (.4331" diameter ) ARP studs wouldn't thread (M11x2.0) into the block without binding/galling - whereby the stock bolts go in without issue. Yes, the threads were chased (6 times per hole) and blown out (with compressed air and solvent). Measured the stock bolts (.423") and the ARP studs (.430") to find a .007" difference. The basic pitch matches in both the bolt and stud, and each measures out at 2.0 with a gauge. ARP's tech line basically said they aspire to a "higher class of bolt" (let's say a Class 3) which may be causing the problem where a regular production class threaded hole (let's say a Class 2), thus the variance in tolerance from one to the next is the root issue of the interference fit. Another possibility is the block is sitting around 10-13*C (~50-55*F) causing the tolerances to close up - but that is a bit of a stretch (bolt pun fully intended).
Thread class article:
https://www.fastenal.com/content/feds/pdf/Article - Screw Threads Design.pdf
Rather than mope - I just cleaned the orange sealant/thread-locker goop off the threads of a set of new GM bolts, coated them with ARP Ultralube, and torqued them down. A pretty easy process by comparison - except that I am out $200+ on the ARP studs. Using this process these bolts were good enough to hold the heads down on my Procharged LS2, and they will hold this thing together.
At this rate it is going to take a week to build this thing...