I can't even get my biceps to take much oil...

I've started to move away from that spot-injection site..

The pecs are the way to go if you're just injecting (~1 - 1.5cc)

Quads, Glute, Pecs, Delts = the easiest spots to shoot IMO. (and given x2 each, there are plenty of injection spots there to help avoid scar-tissue build-up: even with ed/injections.)

-VM