i just bought an XE274 cam and i would like to know how rough the idle is and how it will be on the street ( vaccuum for power brakes, etc.)

forgot to say i have a t-5 tranny, and a 750 vs holley carb, and 3:73 rear gears.

I really just want to find out if it is a good carb for street driving.

cam, not carb ....sorry

I used to have one in my 400.

It ran great. It didn't exactly make the motor "lope", rather, it made it sound "angry", like it wanted to jump out of there and kill something. People loved the sound of it. I ran it with a Holley 800 CFM manual secondary carb, T-5 and 3.73 gears. I smoked about anybody I wanted to on the street.

My brakes worked fine with it.

Now keep in mind, this was a 400, not a 305...

i have a 350, not a 305

I think that's the cam in my engine. It pulls like a mad man from 3000-6000. The idle at 750 800 rpm is smooth as glass. At 500 it starts to get a little rough and shake the car pretty good. That 750 might be a little excessive if you don't have the heads to go with it. The problem I'm running into right now is that the cam is a little too big and the carb is a little to big and rich. Also idling at 500 the brakes get a little iffy, but whith it idled up I've never run out of pedal. Just don't crack those throttle blades when you're trying to brake. That just kills them. I do a lot of two feet driving and sometimes I ride the accelerator a little.

i have trick flow 23* heads. they should flow enough

It will have a decent lope, but will idle just fine and power your brakes. I have the next size up XE284 cam in my 355 which has quite a bit more duration and lift, and it still idles OK at 1,000 rpms, no less than that though. Pulls about 9 inches of vacuum, just enough for power brakes. I'd suspect the 274 would pull a couple more inches of vacuum.

I am running the XR282 with the setup listed below. It runs good, but below 1k rpm, the brakes suck. After that the car roars. I love it. I think the XE274 would work great in your setup.

That cam and carb will work nicely with what you have.
The carb could use some tweeking though.
Buy a set of secondary vacuum springs to adjust the opening rate. Buy the secondary metering block kit to replace the metering plate, so you can adjust the jetting.
Try 70/72 primary and 78/82 secondary jetting.
The cam should have a somewhat lopey idle, but not unmanagable.
Power brakes should be ok just don't turn your idle speed
to low. About 800 rpm at idle.