trying to figure out if this will work

do you mean stock exhaust manifolds?

it should bolt up to (im assuming you meant "HEADERS" not heads) the stock headers. But, honestly id just buy a set of headers while your at it. The best thing to do is to buy your headers and intermediate pipe from the same manufacturer. Get Longtubes is you have a manual. SLP makes a nice set of stainless longtubes!

the midpipes (X/H) usually bolt up to the Manfold/headers. if the pipe is full length and not shorty it should bolt up to the stock manifolds as far as i know sLP dont have any clearance problems with there cats i heard somthing about magnaflows midpipes cats being to big but im not sure.. SLP makes great products id go for it unless you want to save for long tubes then shorty x/h pipe