5inches at idle? What was your manifold vacuum at that time?
I'm surprised too.Have you measured the LeakDown? You must have a heckuva ringseal.
I got numbers half that high when I installed Plasma Moly rings on my KB107s with too tight ringgaps. It would lock up at shut-down, and the starter couldn't crank it for 15/20 minutes. I had to take the engine back out and open the gaps up some.
I gottamention tho;
I get EVACs at the track, cuz the gains are more than significant;
but if this is a streeter, anything more than 400/450 hp, IMO, is waaaay overkill, so; are you sure you want to be looking for the last few? I mean 5 inches is enough to suck something in somewhere; and the longest I ever stand on it is 5 or so seconds.
IDK; 5 inches is a lot. Yur engine is gonna implode,
:lol:
