new motor

[narleycarley]

I'm putting in a new big block with demon carb with th400 in my truck that had a factory 305 with th350 with ac. I dont have ac now.

I'm trying to figure out what vac lines i need to run and basically where i'm plugging them in. I'm guessing the vac line for the th400, line for the brakes, and line for PCV and that's it. Is that it? And does it matter what port they go in to the carb?

Also, do I need to run a line/hose from the top of the water pump to the intake right at the thermostat? I've seen motors with that hose ran, and without.

[SSC's76]

PCV, brake booster, vacuum mod for transmission and one for the distributor vacuum advance are all you need. Demon carbs are picky some ar just like holley carbs some arent. Id suggest using the large port on the front of the carb for the pcv valve. I'd suggest getting a vacuum T for the brake booster and trans one you screw into the manifold. The vacuum advance can go off either a ported or full vacuum source from the carb. The by pass hose on the water pump you want to have hooked up. Its will allow coolant to circulate in the engine properly.

[narleycarley]

Originally Posted by SSC's76

I'd suggest getting a vacuum T for the brake booster and trans one you screw into the manifold.

Thanks alot! that was good stuff. One more question. where would said manifold port be that you said? wouldnt want to tie in to the water side of it.

[SSC's76]

Well if you select the correct port for manifold vacuum you will be fine. Most intake manifolds have at least one vac port in the rear of the intake to screw in a vacuum T. I dont have any detailed pics since my truck doesent have an automatic or power brakes. Basicaly any port behind the carb on the intake will be vacuum if its about the size of a dime.