Hey guys- sorry for the delay. I'm not able to post on Stangnet every day. Of course, our sales/tech associates are available 14 hours a day, 7 days a week at 561.588.6630 so if you need an immediate answer, please contact us there.
I wouldn't say we "recommend" for a customer to stick with the stock
control arms, but it is an option. The factory a-arms can be used with stock style springs if you choose our k-member kit which includes upper spring perches. In fact, the factory a-arms, springs, struts, steering rack, and cc-plates can be used with UPR's tubular k-member. That said, our complete k-member kit with tubular a-arms, and coilovers, used with quality struts and UPR cc-plates is a great and versatile setup. It's been used on everything from 7-second drag cars to high mileage street cars. In terms of durability, we've sold thousands of these k-members and haven't had a single failure.
And from a personal perspective, although people like to take shots at UPR's reputation for whatever reason, I can tell you this- I have UPR tubular k-members in all three of my Mustangs. My babies ride in my cars. I can assure you that NO job is worth risking my kids' lives just to please my boss. I use UPR Products on my own vehicles because they work well, reliably.
My boss's name is Jeremy Martorella. He can be reached at 561.588.6630. I would urge you to contact him right away.