Man...what an event. Finally got the car back after 350 install.

Problems:
1) I used aftermarket exhaust manifolds and they said the 305 y-pipe wouldnt fir correctly so they had to fab a custom y-pipe. ($200)

2) I had one of my fans wired to a manual switch in the car. The other ran like stock off a hypertech fan switch in the block. The miffed (of course) the wiring on the manual fan and ran it hot in the shop to like 230*. I couldnt even cool it down with both fans running while driving it home. But I rewired the fan switch this morning and it seems to be ok now. Temp guage sits at around 10 o'clock. Not too hot this am but I drove it around city streets for a while and hope the temp wont climb too high on hotter days.

3) I got the car at the time the shop closed yesterday and they said they had just installed the 350 prom and hadnt had time to test drive it yet. I drives ok. But I notice some hesitation sometimes on acceleration and sometimes the rpm's jump around at idle (between 700-1100). Yesterday when I was driving it, it died twice at a couple red lights. Not sure what this means. I had a Holly afpr installed and I dont know if they set the fuel pressure correctly (I used reman'd 350 injectors). Could be the fuel filter too. Havent replaced that in a year maybe.

After installing the prom, should they have set the timing?

 

Well as for your cooling problems, you might be low on water or have a bad thermostat. The fans not being on when you are driveing dosent realy make a diffrence, it should only warm up when you are stoped. There is enough air coming through or from under the bumper wile driving to keep the water cool.

 

The water/coolant looks to be pretty green, i.e rich with antifreeze. Usually I dont go with 50/50. I like 75/25 with a bottle of water wetter. The stat is new, but its an off the shelf piece from pepboys. I wanted the 180* stat but the only hi-perf one was a 195* (too hot!!). So I got a cheap 180* stat.

Its prob a crappy stat combined with too much antifreeze. Everything else seems to be working fine. The water pump is aluminum and only 3 yrs old. The rad is a NOS but its brand new. The fan motors are also brand new.

Would it be appropriate to check timing after installing a new prom?

 

water cools better than the glycol does

make sur eit builds up pressure and holds it,

pressure helps cool too

 

Pressure doesn't help cool. Pressure keeps the coolant from boiling, boiling reduces cooling because heat transfer doesn't work very well in a system designed to move liquid around.

 

So pressure helps the cooling process,

 

try anyother thermostat... i had to buy 3 to get one that worked...
such a pain... I went with a failsafe model 180*

 

No... pressure raises the boiling point of the liquid in the cooling system. If the coolant boils, it becomes a vapor (steam) which doesn't do a great job of cooling uhh... anything. The added pressure prevents the coolant from boiling by raising the boiling point of the liquid.

 

I think everyone understands that the pressure does not cool the liquid, but it does help the cooling system. For example, if the pressure in the system raises the boiling point that means it will take the liquid longer to reach that temp(i.e boiling point). If no pressure was present the boiling point temperature would be lower and the liquid would boil faster thus turning it to steam, which does not do us any good. So the pressure that is present does actually help the sytem.

Jay