Schumacher headers are designed to work with an automatic transmission. They have to be modified to work with a four speed and they don't fit a Lakewood bellhousing at all. But they are close enough that I decided to give it a go. I tried some TTI 1 3/4 headers and they were a complete no go. I've tried other headers over the years that also didn't fit which is the reason I ran cast iron manifolds on the car for so long. I'm pretty sure that I can make these Tri-Y headers work this time around. It is just a fab job at this point and I know guys who can fab.