I wouldn't be afraid to run that 800 on my 367. I currently run a 750DP.
And I have run that 292/108 cam in my 367 with the same 750DP, with the same 10.5 PV; and idling at 750 and less.
You have either
A) a serious vacuum leak or
B) the carb is pissing gas down the barrels, or
C) the low-speed circuit is not working
As to A) this should be an easy find.
As to B) this is even easier to find
Only C) will be tricky. Start by advancing the timing to ~18* at 800 if she'll go there. If not, then just keep advancing until you can start backing off the idle speedscrew.
That cam likes a lot of idle bypass air. So take the carb off and close the primaries all the way, then make sure the secondaries are closed up tight but not sticking. Next crack the secondaries just a little with that stoopid little screw that they put in there that you can only access with the carb off; I think it's called the secondary cracking screw. Myself, I take it outta there and turn it around and install it downside up. Now you can adjust it from the top. Of course the engine will have to be shut off, and the secondaries WOT,to do it,lol.
Anyway; after the secondaries are cracked maybe 1.5 turns, then open the primaries until the transfers show square to a little taller than wide. Then readjust the mixture screws to 1 turn out from lightly seated. Finally make sure you got the right basegasket and that it's in good shape, and don't put it on a spreadbore intake.Well you can with the right adapter and the right gaskets that properly seal everywhere.
Now; after the carb is installed DO NOT TOUCH the speedscrew. You will be setting the idlespeed with timing and idle-bypass air, namely the secondary cracking screw.With the extra timing it should idle. If it doesn't, then go back to the ABCs
Course it goes without saying that the fuel levels have to be correct and stable,and the gas is fresh; right?
If you still can't bring the idlespeed into line, I suspect the lowspeed circuit is not working properly, that is to say the transfers are not flowing. You will have to take the front bowl off and verify the right gasket was installed, then you may have to go thru that circuit. While the bowl is off, you can check for a ruptured diaphragm in the PV.
That's all I got for now.
Good luck.
