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you didnt state what kind of cam and intake you have.....
in the temps were having this summer, it should fire up and run very smoothly immediately (unless you have a single plane intake and ONE HELL of a cam..... i.e. NET intake duration of 250 degrees or more)
I've always believed a 750 vacuum secondary (much less a double pumper!!) is too much for a 351 unless it is a pure quarter miler......but it should be able to idle; 750 cfm on a small block affects driveability more than idle.
I built a 351C with a cam spec'ed out at 230 net duration....at 900 it idled like a stocker and the power brakes worked great!!!
Take vacuum readings....if the cam is not outrageously big, it should pull at least 14" of vacuum at 900 rpm....if lower, ensure the power valves in the carb are rated a few inches lower than the idle vacuum once the timing and mixture are right.
If not, I'd work with the initial timing and idle mixture adjustment, and if it still idled crappy, I'd do compression tests
BTW, you did pre-oil the engine and follow the initial run-in instructions from your cam manufacturer, and youre sure the cam timing is correct?
(and degreeing the cam when installing it is a good idea)
in the temps were having this summer, it should fire up and run very smoothly immediately (unless you have a single plane intake and ONE HELL of a cam..... i.e. NET intake duration of 250 degrees or more)
I've always believed a 750 vacuum secondary (much less a double pumper!!) is too much for a 351 unless it is a pure quarter miler......but it should be able to idle; 750 cfm on a small block affects driveability more than idle.
I built a 351C with a cam spec'ed out at 230 net duration....at 900 it idled like a stocker and the power brakes worked great!!!
Take vacuum readings....if the cam is not outrageously big, it should pull at least 14" of vacuum at 900 rpm....if lower, ensure the power valves in the carb are rated a few inches lower than the idle vacuum once the timing and mixture are right.
If not, I'd work with the initial timing and idle mixture adjustment, and if it still idled crappy, I'd do compression tests
BTW, you did pre-oil the engine and follow the initial run-in instructions from your cam manufacturer, and youre sure the cam timing is correct?
(and degreeing the cam when installing it is a good idea)