I feel it's your 318 intake more than anything even gasket matched the runners are too small for the needs of your engine. There designed to work 318 heads that are lucky to make more than 325 hp without serous porting.
I'll agree with this. I wish I knew that was the case before had. it was a carb and intake that my dad had so I used it.I didn't know the intake was for 318. good to know going forward
I'd be interested in seeing another dyno chart and specs on a similar engine to mine just to see the differance if anyone happens to have any info to share
