this might be a dumb question but how dose air get to the carbs with the hood on, the reason i ask this yesterday while working on the motor i noticed the motor would idle at 1100 rpm without hood put hood on the rpm will drop to 700 to 800 rpm.
If you look closely the hoods are vented. Sounds to me like yours is plugged or it was just unrelated that you RPM dropped at the same time the hood went on. If it fit so well that we lost 400 at idle we would never get to WOT. Best of luck. Rick.
I'm certainly not familiar with your engine but I have to believe the engineers would have figured something clever by 1977. If you think about it they just would not run if the cowl was air tight. Rick.