Last year I rebuilt and installed an SN89 on a carbureted 306. The motor is fairly built with windsor jr heads, rpm air gap intake, long tube headers, etc. The cam is a comp cams 270H magnum. It is pullied to 40k rpm at 6k engine rpm. I am using the new high output impeller and rebuilt to specs. It has about 40 inch pounds of resistance. I'm only seeing 3 or maybe 4 psi max in the intake. I've tested for leaks and it's only leaking through the throttle shafts a little - could I be losing much boost through there or do you think my cam is bleeding off boost from too much overlap? I'm also at 5200 feet elevation. Could that be killing boost as well?
I was thinking this would make 6-8 psi on my small 306. Any help or ideas would be great. Thanks.