Page after page after page of why NOT to build a 318, yet still no one will recommend a "one step up" hydraulic flat tappet cam that doesn't kill the low end or MPG.
Perhaps we should concentrate on improving 0-60 times rather than increasing HP.
Once you move away from the stock cam, mileage bets are off. Anyone who can tune a distributor and carb can lick 99.9999% of mileage issues.
Any HFT duration of 218 and lower.
No converter change needed.