Chevy & GMC Vans

ok all, i had my van to a garage today to fix a simple donut gasket leak. they claim that my y pipe takes a spring kit. is this true? the autozone doesn't show one, and i don't remember ever taking them off from the start. i need some help../.....

so out of the research i've done, i guess my van does take the spring kit. so i picked up a gasket and springs/bolts and the shop claims they need the van for 2 hrs. i was going to do the side that is leaky for now. i know i can do it in my driveway, on crushed stone in probably an hour at the most. these shop must take every customer and label them as sucker.