i have 77 chevy with 89,000 miles, had 5.7 350, high performance cam, lifters timing, other day it ran hot and shut self off. i let sit over night put gallon antifreeeze in radiator drove few miles home. in that few miles ran hot again. i replaced thermostat water pump temp switch and pcv valve due to fact its cheap and i was working on motor might as well replace it any way. i also replaced stock fan with a electric fan i wired it up to ignition so that it turns on when i turn key and off when i turn off the key. the motor still is running hot. and when i come to stop it dies. hesitate to start after it dies and hesitate to start for first time each day. before running hot it started no problem never died. what are the issues

 

Since you made a larger engine, you also need to increase the cooling capacity.

 

it has a new radiator in it. not sure if its bigger than stock. i replaced thermostat with a 160 degree thermostat.

 

1. Clogged water passages in the block.
2. Air in the block.

and really I think your timing is off with that Hi-Pro cam. You may want to retard the timing a bit. I dont know to what but different than where it is.

 

First off all, is the electric fan a dual fan? Second how many rows in the radiator?

 

not a dual single fan 12 inch, auto parts store said that was fan i needed based on motor. rows not sure ill have to look the truck threw power steering pump and alternator belt yesterday going to work

 

I think you'd better revisit that. My 3.1 has 2, 12" on it.