1600 Twin Port Cylinder Engine Tin Screw Removal

I managed to get my engine in last night but I had to do it with the cylinder-top engine tin still installed. This put a lot of stress on the new rubber seal around the engine bay and I had to tweak it a lot with a screw driver.

At one point I lowered the motor back down to try and remove the tin, but one of the tin screws (rearmost on both sides) is right under the intake manifold pipe, with no chance of getting a screw driver in there. I couldn't help think an allen bolt or normal bolt would be perfect here. Obviously I need an offset screwdriver to get it out, but have others replaced this little screw/bolt with something else ?