Ignition Issue????

He just stepped up in cfm and his engine has the gumps to take on the 800 fine. It is alot of cfm, however, it can be tuned for the cars engine. (I ran a 800 on a otherwise stock 318 for a month till I grabbed a 600 cfm. It really wasn't a problem.)
It's not the cfm that kills, it's the poor tune of a carb that kills. Wacking the throttle to WOT can kill low end with the supper sudden drop in velocity. Not the problem here.