Cam for torque question

Lustle said
That XE268H should make tonnes of vacuum. 15.5 inches at 850 idle. And it's a known torque maker. Lots of guys drop those in 360 truck engines to make good bottom end torque.

I'm surprised at the power you're making. Your DCR is 7.85. That cam's not bad. Decent heads. Yet you're only making 280? Usually that cam is good for 1hp per cube. You should be making way more torque as well. That cam is a torque over horsepower maker.

I'd say you need a good tuneup. Check ignition, timing, carb, etc etc. You should be making more power. And shouldn't have a problem running vacuum anything.

As reference, I run the XE274H in my 340. And have no problem with power brakes and steering.

Well, A little more information and in retrospect... I bought this holley carb from summit. Installed it at the time of rebuild...the engine had never ran. Broke it in on that carb. It never really ran right at idle and needed to be at 1200rpm idle to stay running in gear. Sprayed carb cleaner around the carb base and it stalled the engine. I took the carb off and found that all the throttle plate mounting screws were loose except 1. When I turned them, they let out a "snap" as if they were installed with a thread locker but they all turned in after that about 1 1/2 turns each. I put it back on and the idle settled right down to where it is now.

Now you've got me re-thinking this carb. there may still be a vacuum leak somewhere. I do see fluctuation on the vacuum gauge but I attributed that to intake and exhaust pulses. Also, due to the Indy RHS heads height, the air gap manifold doesn't fit perfectly. I had to use 340 intake gaskets to make it work. cant detect a leak with carb cleaner or propane there.. Perhaps a trip to the machine shop with the intake in hand is in order along with a carb teardown.