Just thought of more. The truck engines in the 80s did not have the same smog limiters as the car counterparts. Not sure if your 84 360 was the heavy duty version... in could already have bigger valves and intake runners... might want to research that before getting too serious on after market HP goodies. Carb likley su_hs being from 84... But the heads and intake may be better than the average car 360 from the cordobas etc.

Just something to consider...

Dave