I have tried everything. the truck will idol great a little sputter but still good. the connections in the distributor were dirty, i cleaned them up. pcv valve is rattleing like crazy the air filter was plugged. no apparent vacume leaks but the truck will still stall as soon as it goes into gear. I want to check the fireing order but not sure what it is. also should I try to increase the idol to make it rev higher will that help

For the 351M and 400 it will be 1-3-7-2-6-5-4-8
For the 255 and 302 it will be 1-5-4-2-6-3-7-8
#1 cylinder on your motor is front passenger side, 2,3,4 working your way toward the back. #5 cylinder is front front driver side, 6,7,8 toward back.
If you look at your distributor from the front of the truck and call the very back north, then #1 is north-east. Rotation is counter clockwise.
Also maybe invest in a timing light and check your timing.
Get yourself a Haynes manual. It's worth the $15 to have the answers to these simple questions at hand.

The firing order should be cast onto the top of the intake manifold somewhere.