I believe, that without the cast-in "hump" of a true side oiler block, it would require an external
oil line along with some serious drilling with special long drilling equipment to add the needed passages.
Unless the intended use is NASCAR ( know they don't run in NASCAR anymore) or other serious high speed track time, I think it is a waste of time and money. That old center oiler is a pretty tough piece just as it is.
Instead, I'd spend my money on blue printing, balancing,
oil restriction to the top end and some good ARP rod bolts. Oh and get rid of the sodium filled valves if it still has them.
Other than that, I wouldn't fool with it unless the user intends to sit in the driveway and freewind the engine to 8 grand in which case it would blow anyway.
Frankly, although I went whole hog and had the requisite S/O, I did it more for braggin' rights than actual need. The center oiler would have been just fine for my use which was mostly street with a little playday type track time.
I'm pretty sure that most guys fall into that category. Further, most owners don't have the capability of driving a Cobra hard enough to hurt the engine....including me. I guess if desired, it could be done by just over revving the snot out of it in first gear, but how many people are that dumb?
Retraction.....there are people that dumb, I just don't know of any that have Cobra cars.
Al