Hello all. I have a question. I have been running a holley 750 dp on my 505 with no power valves, thats the way i bought it. now i have purchased the new holley 850 ultra hp. It came with a 4.5 power valve. I do not see any vacuum ports on this carb nor do I need any i do not run power brakes or vacuum advanced dist. Now I was wandering how to get a vacuum reading to find out if that will be the correct power valve. Also on my old carb I was running 79 jets in front and 82 in back. I have read that if I run a power valve my jets should be bigger. I noticed the 850 came with 84 in front and rear. thanks for any info, tips or tricks with this new carb