93 3.4 camaro stalls when hot and wont restart until cool

hey, i have a 94 3.4l camaro automatic. about 3 weeks ago i sprung a coolant leak from the right head gasket and replaced both head gaskets and cleaned up the heads, valves and replaced the valve seals. now starts easily when cold, and runs great even when it gets hot, until i try to shift it out of park when hot. as soon as the trans engages the gear it will stall and it is very difficult to restart i have to crank it for sometimes 30 seconds and feather the gas to get it to start. in some extreme cases it will not start and i will kill the battery trying. when this happens it will backfire both through the intake and exhaust occasionally. the odd thing is that once it cools down it will start easily again. if i keep my foot on the gas a little bit i can keep it from stalling and then if i slowly let off the gas it will idle normally even in gear.

background:
new cyl. head, upper & lower intake, exhaust manifold, throttle body, valve cover & EGR gaskets.
new coolant temp sensors, thermostat, upper radiator hose, spark plugs & wires, valve seals
new lifters (ill explain)
fixed wiring problems at fuel injector connector, ignition control module connectors & ICM & PCM grounds then when problem didnt go away i replaced ICM for fear that it was fried
noticed torn insulation at camshaft position sensor harness so i replace the sensor & pigtail
new O2 sensor due to coolant damage
map sensor replaced 2 months ago
egr replaced 6 months ago
ignition coils replaced 1 year ago

when i set valve lash, i followed the Chevy manual which said to go to zero lash + 1 and 1/2 turns and that resulted in no compression on any cylinders
thats when i realized that all of my lifter plungers were seized at the top of their travel so those extra turns just compressed the valve springs. so i bought new lifters and reset lash again to gm specs this once again resulted in the valves being open too much when the lifters pumped up. so i followed the advice of a gm tech and set each cyl indepently and went just a half turn past zero lash.

On hot restart:
all cylinders have spark
with a scan tool all sensors check out ok.
while cranking tech 1 scan tool indicates between 20 and 30 ms of injector p/w? (seems extremely high to me)
engine occasionally wil quit cranking for a split second almost as though it has detonation that is trying to spin it backwards and it wil bacfire through the intake and exhaust
fuel pressure is within specs both engine off and when at idle and pressure stays at 42 lbs for about 15 minutes and then dwindles off.(engine off)
tried to check compression yesterday when hot, but my tester was acting screwy the first cyl i checked was # 2 checking in at a whopping 30 lbs, but i think my tester wasnt sealing properly when i checked the next one #4 the tester said 0 so i went back and checked 2 again and now had 0 there also
at this point i threw my tester somewhere in the yard and went inside

if you need anymore info from me im sure i have some more i just couldnt remember anything else off the top of my head. i would greatly appreciate any help any of you can give me as im kinda on a deadline w/ this thing.

one quick thing to check, is your fuel injector resistances, which can be checked with a voltmeter, hardley takes any time, and could very well be the problem. make sure all six injectors are the same resistance value. you might need to wait until the car is hot and acting up, as in cranking but not starting.

try changing the ecm with a friend or somebody

ok back w/ the injector values w/ engine @ operating temperature

#1 13 ohms
#2 13
#3 13.1
#4 13.1
#5 13.1
#6 12.8

gm specs is 11.8 - 12.6 @65 degrees F but they dont state what the allowable variation is so i dont know for a fact if #6 is bad. once the engine cools ill check all resistances again and double check against specs

as far as the pcm theory goes, i tried borrowing a pcm, but i couldnt find anyone w/ one and since the car ran fine before i changed the head gaskets, i figured it was probably something i touched so ive kinda dropped that idea.

FYI some techs had suggested a possible vacuum leak could be the cause, so i threw a tester on it and came up w/ 18 in. Hg but i couldnt find any specs on this so if anyone knows it off the top of your head let me know

Edit: forgot to mention that its not only when the trans egages a gear that the car stalls, also too much strain on the power steering system will kill it, not necessarily turning it to the lock, but turning it too quickly at idle will do it too. also adding any electrical load like turning on the blower motor or headlights will make it stumble but as of yet not stall it

will the same thing work for my firebird? its a 97 auto also. and sometimes when i shift into reverse everything just turns off. but it starts pretty quickly though