YOur buddy's engine got grenaded probably ebcause his shortblock wasn't stout and had some miles on it. Like when I did a head/cam swap on my camaro. Trick Flow Twisted wedge G2 heads, Scorpion intake (6500 RPMs)and a comp cams extreme energy cam (280 duration .510 intake .494 exh), and 1.6 int, and 1.52 exh roller rockers. The heads had 62cc chambers and my piston rings weren't that good from an oil experience (plastic sender line to oil pressure gauge was touching the header on a 45 minute trip...TOAST). So, I blew my timing chain cover gasket, and iol pan gasket. Blowby was creating way too much pressure, it ran hotand I had to part it out. The engine was junk.

THat is why i am going to swap a cam when i swap shortblocks. Plus i am either gonna get my heads reworked, or buy higher flowing heads (making sure to get dual valvesprings). My roller rockers will be 1.7 intake and 1.6 exhaust. WHY DIFFERENT RATIOS? Because i plan on a high duration camshaft and I want the exhaust valves to close sooner (before intake opens)so there is no overlap (when intake opens before the exh closes). And when doing a cam upgrade, you are really matching the cam to your intake and head flow rate. So, my cam was chosen AFTER i chose my heads and most importantly intake. If your intake can't get the right amount of air into the chambers at certain RPMs, then the cam upgrade was not maximized.

Bottom line, heads and intake must match camshaft not the other way around. If you want something quick, do 1.7 RRs with the stock setup.