Originally Posted By: leroyd92
There's no sensors nor computers...
I personally don't wanna mess with it. But if there's mountains to gain id be open to the idea
Many of those engines were down on power, not because of the bolted on emission controls, but because of the internal design. Cam timing, valve lift, and duration were all extremely conservative. The compression ratio was also very low. In addition, the valve sizes and port sizes conspire to limit output.
However, if you have one of the old style catalytic converters on it, and small, single exhaust/muffler, they are quite restrictive.
For a while, owners of these were installing free flowing exhausts and the aftermarket throttle body fuel injection systems. That did help the power and MPG, plus eliminated the hot start issues some of them had.
EDIT: Those in the know, replaced those engines with the marine versions that produced 400HP stock.