Hi. No hate for the swap, lots of guys dont like the 301t, but they can be made to run pretty good for what they are... & for a somewhat rare pace car i hope you at least keep the 301t if its original to the car, kills the resale value once its gone.
To answer your question, yes you can run full length headers with the 4-speed. I use & suggest hedman #28150, they are excellent quality & install & fit great. They are made to accept the 4 speed linkage, there are other brands out there but they are much more expensive. Summit has the hedmans for the best price & free shipping. Just follow the instructions with the headers, they are easy to install if done right, & are not a tight fit at all & after a few heat cycles retorque the bolts. My hedmans are going on 10 years with the supplied paper gaskets & are leak free. Also, use a good 2.5" exhaust with an H or X pipe if possible & straight through mufflers, flowmasters are terrible for performance. I like pypes race pros or dynomax ultraflo's.
