part number

My pump support is cracked and needs to be replaced so that I can mount a new intake grate on it. I cannot find the exact replacement Pump Support (271000954)for my 99 GSXL but there is one on eBay from a 98 GSXL (271000866). The seller also has the part number of mine as interchangeable but in...

where can i find the model or serial or part # of a jet pump assembly to cross reference it for use on other crafts. or do u just base its compatability on size and shape? thanks