Valiants with V8s

Most of the early \6 can be over bored 0.100" to 3.50". Direct Connection had a stroker crank too so 242 CI was do'able. Finding a 3.50" piston may be tough.

But still, the biggest bang for the $$$ is to mill the head 0.060" and port it some. As cast the ports are very rough and core shifted so just port the pockets and blend the ports and you will see (Butt Dyno) some good gains.

But since we are talking swapping a V8 into a 68 Valiant with a \6, most info is in the above posts above. Finding correct exhaust manifolds to fit, motor mounts and oil pans, throttle linkage, kick down linkage or Z-Bar for clutch....... Good luck.

I'd just make sure the bottom end is solid, deck the block and head square, some ARP head bolts and Main bearing cap bolts and put a Turbo on with 7-10 PSI. Easy 225 HP anytime you flex that right ankle. Lots of room for a turbo and intercooler.

\6's have oiling issues. A lot of windage oil splashing around so a deeper sump and pickup tube helps. Put a scraper bar inside the pan too.