I think everything is good now. It's back together and I was going to start it tomorrow evening and let it run a bit and then change the oil, then test it out. Thanks for the help! And for anyone else who might be seeing this, this site helped me out immensely. How To Replace Intake Manifold Gaskets On A GMC Jimmy 4.3 Liter V6 To Fix A Coolant Leak - GM Truck Engine Repairs

 

Anything I need to know when starting it? What about the fuel lines?

 

Fuel lines will self bleed as soon as the pump comes on. As far as starting, usually works good if you turn the key Fire it up! Lets hear it RUN.

 

Alright so it started up, sounds good, but its overheating while it idols and doesn't seem to be pulling any coolant and isn't throwing heat. I'm going to change the oil now but any ideas?

 

Sounds to me like the thermostat

 

I haven't hit the throttle at all yet, could the thermostat just be stuck and clear up once it revs up a bit? And any procedure for getting coolant back through the system in general as far as getting air out?

 

usually with me it starts heating up probably about the 3/4 mark then it opens up especially when its low, as for putting coolant into it i always turn it on and leave the cap open when the t-stat opens it goes fast from the radiator and sometimes after its full i accelerate the throttle a little so the coolant level goes down a bit and put some more and install the cap back but its probably not the correct way to do it

 

Alright it had just gotten to 3/4 and was hanging there. And radiator cap or filling tank? Thanks a lot!

 

i always do the radiator cap, if it doesn't cool down i would replace the t-stat

 

Might try jacking up the right front corner, (to get the radiator fill hole up higher) then hold rpm around 2K. When it burps and the level goes down, keep filling it up. Jazzing the throttle helps to dislodge air pockets too. Once it's full, put the cap on and THEN let it idle. Then fill the reservoir to the "MAX" line. Both heater hoses must be hot, (too hot to hold for more than a few seconds) and about the same temperature.