96 Blazer 4.3 2wd 245k miles, stalls intermittantly

In garage fires right up and idles great, can throttle through and no problems. Get it on the road and it just dies randomly (4-5 times around the blocks, sometimes takes a few times to restart (it does crank). Now back in the garage and it fires right up time after time and runs again no problem.
Back to the streets and yep it stalls.
No codes are thrown

Checked fuel presure, steady at 52ish at idle. Do not know while driving, as the hose on gauge is to short to get to the windshield

A little background info...

Truck has been sitting for 12 to 18 months (trans)
Prior to the trans going out replaced plugs, wires, dist, cap & rotor, fuel filter, MAF cleaned EGR, and ran 2 bottles of seafoam through intake, cleaned throttle body.

Finally, got trans rebuilt and in the vehicle. had a leak so I resealed the oil pan and timing cover since I had it all apart I put in new timing chain.
Cleaned all electrical connections and are all good and tight. Wirebrushed all ground points on truck.

What am I missing??

 

52psi is a little on the low side.

Just as a quick check, make sure that the fresh air make-up hose is connected to the back of the throttle body 'hat' (piece that connects the intake tube to the throttle body). If that is disconnected, it will allow air into the throttle body that isn't being seen by the MAF sensor and can cause the symptoms you are experiencing.

 

OK update: found that fuel pump is not priming with every key turn. Can someone tell me where the fuel pump relay is for 96 blazer 4.3?

 

Here's a view showing the relay center behind the glovebox:

 

OK so after taking the time to follow ALL of the diagnostic instructions (rather than jumping around), looks like my fuel pump AGAIN. Got the tank dropped today and guess what I found?? Any guesses?? You got it there is an Airtex Pump in there. I think I may have read here once or twice or more, that these $uck. Why am I going on... Maybe someone else can avoid this costly mistake. You may save $100 or so now, but when you are replacing it again and you will!!! You have been warned!!