1989 Ford Ecoline E250 had a 302 v-8 with 4 speed auto transmission
I'm replacing the V-8 with a 1988 rebuilt 4.9 L 300 ci inline 6
Problem: Cylinders 2, 4 & 6 are not firing properly.
I have the 1989 service manual covering both V-8 and I6.
I need to know the top dead center No. 1 position after
compression stroke. Are pistons 1 and 6 supposed to be
at top dead center or are pistons 1 and 5 supposed to be
at top dead center. I cannot find this in the manual.
Engine is currently set with 1 and 6 at top dead center.

FYI: I have already checkec and eliminated the following possible problems:
1) distributor firing order is correct
2) compression checks out at 150 on all cylinders so unlikely to be a lifter problem
3) I rotated the engine and checked both exhaust and intake valve closure
against distributor - the cam location checks out with the distributor rotation
4) I have traced out and check ohms on all the rewiring I did and found
no problems
5) I have no means of checking the computer or the distributor module
6) I do not think I have a means of checking the injectors and I don't
know who to trust to buy new ones from
7) I've checked vacuum to the extent I can with 3 cylinders not working
properly

I do not know if it is not firing properly or is not getting fuel properly.

Any thoughts on what I should try next?

PNJ89

 

#1 and #6 TDC occur at the same time. This is built into the shape of the crank, so it is hard to get wrong without breaking the crank.

I would suspect you may have an EFI problem which is out of my realm, but I posted to say I am impressed by your trouble-shooting process. Good luck.