Fuel pump pushrod length

[av8coupe]

I am putting an Edelbrock Slingshot ('32-'48) on an 8BA. Not all of the bolt holes in the intake have holes in the block to receive them but I believe this has been covered elsewhere. I am using a 59AB style fuel pump and mount, which is vented and provides an oil fill. I have tried both length fuel pump pushrods for this set-up and one is too short, the other too long. Is there one that fits just right, or do I trim the long one (and try not to have two that are too short)?