Likely 383 swap-parts advice requested

I got the 440 Source WP and housing. Bit of a shock that it came with no bolts or gasket considering the pic showed it assembled as a set. Once I got it installed, it ran great for about 500 miles, then the impeller started scraping the back of the housing. Pulled it twice, the pump was still solid with no wobble. Wound up having to file down the impeller blades a bit and using 2 gaskets to get clearance. 440 Source recommends using their "thick" .040 gasket since the clearances are so tight. I needed .060 to stop the god awful grinding noise.