help, charging issue

[wheeeedr1]

need help,i have done and checked everything i think, this started when i put a 350 in it, was a v6 car, running a v8 alternator, here is my problem, when i start my car cold all is good but i start driving it and about 6 blocks down the road my alternator quits charging, i have a brand new battery, and alternator, i know it is not my gauge, i have checked the alternator and it is not putting out 14v, my wiring is as follows, from my bat post on alternator to starter solenoid, (put in a ford remote starter solenoid to keep out of heat, from here battery cable goes to the battery, one wire runs back to the alternator to the plug in and the other runs to a fuse i believe on the firewall on the other side of the fuse is a wire that runs to the plug in to the fuse box, i have ohmed it out and resistance is normal, this is the 2nd alternator i have put in it. i have run a ground wire from the alternator to the battery and this did not help. the next day this will all start again. all wiring looks correct to me, could really use some help i can't find my problem.