Added fuel filter... now slow (long time) to start?

[JJorgensen52]

first off, my truck is a 307-2 barrel with at least 100k, probably 200k.

When I first bought it, it would start right up, 1 second or less, even when cold. The started was making horrible noises, so I swapped it out and the noises went away but it still started up quickly.

I added a fuel filter inline over the weekend (right where the line comes out of the cab) this weekend, since I was collecting a lot of rust/particulate in the in-carb filter. The truck wasn't driven much so I figured I'd run one until I pick up most of the junk from the tank.

Now, it takes 4-5 seconds of cranking to get it to start. This says to me either A.) fuel filter has an air leak and I'm loosing my prime or B.) the fuel pump is on it's way out and it's struggling with the filter.

Before I throw a fuel pump at it, am I barking up the wrong tree here?