Just picked up a couple of engine components from ebay and have a cam that is definitely A series, but has the markings O or maybe C (very hard to tell) and 740 on the end, no other identifying markings. Can anyone assist?

Could you give us some background on the engine. That could be 74 degrees, so it might be a factory 74 degree grind. Other than that, try looking at Crow cams, Wade cams, Tighe cams for their A series grinds. maybe a part number will jump out at you.

Cheers for that, the engine came to me in pieces from a datto nut. I'll get some pics up asap. Whats a 74 degree cam,ie stage 2??

Cams are not easy to identify. Often you have to assemble the engine, then use a dial guage and timing wheel and map it out.

Hopefully the O740/C740 will mean something to somebody.

its definatly not a camtech number sam, i stripped my a 15 down last week and its got 1366 on the end. on both of my camtech cams is the grind number followed by the intake lift. ie 640-106 for my 186 holden, ill have a look at malcoms (camtech) book tomorrow and see if 74 means anything in the lift department