95 chevy silverado v8 it starts and runs fine in park but it stalls out as soon as i pit it in gear.

You need to verify the park lock is working, the solenoid is up on the steering column.

On the throttle body is a shift cable check the setting

Does it seem like when the engine is cold it runs ok, then when it reaches operating temp. it starts acting up? (poor acceleration, stalling) When I had that problem w/ my 93 K1500, it ended up being my oxygen sensor. (causing too rich of a mixture in the throttle body)
Hope this helps, Good luck

Well, code 336 is for a problem with the crank sensor, and code 171 is for fuel system too lean bank one which is the side with cylinder one. Since you have checked fuel pressure and I will assume fuel volume is good, the crank sensor or circuit could be at fault.

could have been out of timing could also be fuel pump fuel filters. chevy are very bad about fuel pumps have you checked to see if its getting spark or even checked the fuel pump

have u checked into getting new sparkplugs, wires, coil/coil packs distributor. could even be a timing issue. id start at these things and c if it helps

should prolly tune it up

I have a 97' Silverado 5.7 with a K

Wouldn't happen to be a diesel, would it? If so, do a search on ebay for a remote fsd/pmd module. Fixed my 95 'rado (in less than 20 minutes) with a 6.5 turbo diesel -it would stall wherever and whenever it wanted, without warning.

This is a comon problem with GM cars.Most likely cause is the torqe converter clutch lock up solenoid.