Thanks for the info guys- SS, the cam does have a smaller base circle. It showed up yesterday and I busted out the mics heres what I found- Stock LM7 cam has a 1.552" base circle while the Comp has a 1.497" base circle. A difference of .055"- Works out to be a pushrod length difference of 27.5 thousandths. So heres my plan, While installing my headers the rearmost bolt broke off on the driver bank so I Have a spare set of low milage 862 casting heads that im gonna have milled .010 - .015 and possibly have the rocker pads shaved .005"- Should put me close enough to use stock pushrods and bump compression a bit. (given the fel-pro mls gaskets have the same compressed thickness which Im pretty sure they do) Gonna replace the valve seals and should be good to go- As far as timing set if everyone is using the stock stuff maybe I will just put in the beefier ls2 chain and call it good- Do you have to pull the oil pump to get the chain off? Any other thoughts? Thanks guys-