What are your thoughts on a swap from an xe275hl to a xe284h. 446 10.2:1, eddy rpm heads (no port work) and rpm manifold, headers, auto, 3000 stall, 3.23 and 27" tire, 4000lb charger (with me in it). What vacuum could I expect, I need it to run my brakes, do I need to step up on gear, any input appreciated, thanks.

Aye mate. Welcome aboard. I dont know cams so I have no (relevant) info to share but someone will. You might post the specs of the 2 cams. EDIT what do you have now for idle vac?

cheers Rapid, I have 13" at 850 rpm with the xe275hl - 231/237 @ 50 with .525 lift. The xe284h is 240/246 @ 50 with .507/.510 lift. Both cams are on 110 LSA.

As is 13 in hg is enough to run your PB as you know. The 248 would be a little more duration/less lift. the numbers are close but I ain't a cam guy at all so I cannot opinionate. And the torque converter is going to tie into this. Is this all street or street/strip & are you after more civil manners or more perf & at what RPM range are you wanting an improvement?.

My motor makes 6" to 7" of vacuum on a good day. The power brakes work perfect, 4 wheel discs and the large diameter "thin" factory Bendix booster freshly rebuilt from some place in Washington State.

Sorry, it's been to long for me to remember the name of the place. I had it done 5 to 7 years ago, but there are only a few places that do it.

What are you looking to improve??? Can I vote neither cam?? Get away from the extreme destruction stuff and get a great grind that both you and your valvetrain will be happy with. Call Bullet cams and ask for Tim. I could tell you what will work but this is too easy.

The car has been used only on the street, I intend to get into a bit of fun at the strip, nothing serious just a few times a year with other clowns but I still need the car streetable with a moderate gear as that is where it will spent the most time. The present cam has been in there for 3 years and given no problems, although it has always kicked up a bit of noise.
I am thinking of getting another rear with lower cogs that I can swap over, no money for a gear vendors. I want the cam to hold on more up top. But I need it to work with the 3.23's also so I don't want to go to big. I have adjustable rockers in 1.5's so maybe a solid?
Goldmember, I am open to your suggestions if you care to share them, that's why I posted.

How about the XE285HL?

The HL cams use 0.904" dia lifter-specific lobes, getting more area under the lift curve. The XE is a chevy lobe cam.

R.

Thanks for the reply, my thoughts are I could use more duration to extend my rev range, not sure if I need more lift with my combo?