I ground roller cams for Erson, that were up to .650 lift.
You can get a 454 c.i.d. small block Chevy with a 4.185 in. bore and 4.125 in. stroke on an aftermarket block with a raised cam
Turn them so the hole lines up with the holes in the block.
4 degrees advanced initial, or about 30, total.
Your best bet would be to contact a cam manufacturer for a recommendation. All the popular cam companies have websites.
No the distributor gear that is on the end of the distributor is to small for the big block cam shaft.
The older ones, non ecotec are not overhead cam. they Use the cam in block with pushrods.
NO. Not even close.
If you are asking about backlash, the setting for a solid cam would be on the cam card. Hydraulic cams don't have backlash, they have pre-load, which is usually about 1/2 turn.
Those are 5/16ths NC, so I would go about 45. Also, remember to use Loc-tite on them.
"small block" typically distinguishes between a 2 bolt and 4 bolt main. (Small block= 2 bolt main. Big/large block=4 bolt main) "long block" typically distinguishes between a rebuilt engine that has heads, rockers, rocker covers, oil pump, pan... in other words, complete, versus just block, crank, cam and pistons (short block).
single overhead cam Not true, it is cam in block design and over head valve (OHV).
cam timing will not change ignition timing i would try 8 or 10 degees advance at idle with the vacuum advance disconnected.