Cylinder heads, #1 stop. Outfitted with roller rockers.
All the money is now gone.
A stroker kit and stock cylinder heads? Ehhhhh, the stock cylinder head will only support so much power. The torque will be over the top! The HP increase, not so much.
There’s a video of that exact build on the net. IIRC, it was engine power nation tv show.
If you knew eventually the end goal was to have a stroked 408 with better heads roller rockers ext, do you still think the heads would make the most difference in the short time? My budget will probably allow me to spend about 3000$ a year on car upgrades. So whatever I do to it, it will have to go a full driving season with just that.