Thanks for the replies and I'm sure you guys mean well but I'm quite aware of what my engine needs. I've been building engines for street cars to Pro Comp dragsters for 20+yrs.
The engine in this truck is a 615hp mechanical roller SBC stroker and going with a 2.5" exhaust will caus significant power loss. Anytime your up over 500hp you generally want a 3" system.
Building an exhaust system from scratch isn't hard it's just time consuming. And, since my Millermatic has been acting up lately that is why I'm asking if anyone makes a bolt on 3" kit.
If you cant answer the question then please don't comment.