1991 cfi 454 runs at 210,

[AuroraGirl]

if worried about localized hotspots, you could use a slightly water-biased mixture to get more heat protection but dont compromise your cold depending on where you live.

 

[SirRobyn0]

I think we've gotten a bit far from the original discussion none the less I've been enjoying it so far.

is 13lb what they normally run? seems like a low pressure, but old engines didnt use 16+ psi a lot of newer systems do either

Just so happens I've at work so I looked it up. My 84 lists a 16psi cap, but I wouldn't be to concerned with running a 13 or 10psi cap if the cooling system is in poor shape and there is concern of blowing something. It would lower boiling point a little but as long as it's a proper coolant / water mixture it would still be much higher than 210F

I would bet your truck came factory with a 195 degree thermostat. Aftermarket thermostats are going to range from 160-205 degrees depending on which last person changing it picked. 210 on a factory 195 Tstat I would consider pretty normal. Your truck shouldn't boil until about 250.

Most of these trucks 195 was what they came with. Some of the heavy duty applications got a 180 thermostat but I think emissions pushed the 180 stat out by the later on.

if worried about localized hotspots, you could use a slightly water-biased mixture to get more heat protection but dont compromise your cold depending on where you live.

There are also additive designed to reduce hotspots. No idea if they work, but sometimes folks with classics ask for it.

 

[Craig Nedrow]

Stock mechanical fan BTW. Don't know Aurora girl, what it came with, left it alone, it's all good. Installing my tach in the stock dash. A little tricky, and broke my amp meter pointer, but found all the pieces and will glue it back together, geeeez....I am not fond of this kind of work so I drag my toes, but am getting close, and think it will almost look stock. Aft next, and switch to the Holley carb, got the fittings yesterday, and have everything assembled. Will be glad to get that stuff on and run it a few months, gotta be thinkin' bout winter....

 

[SirRobyn0]

Stock mechanical fan BTW. Don't know Aurora girl, what it came with, left it alone, it's all good. Installing my tach in the stock dash. A little tricky, and broke my amp meter pointer, but found all the pieces and will glue it back together, geeeez....I am not fond of this kind of work so I drag my toes, but am getting close, and think it will almost look stock. Aft next, and switch to the Holley carb, got the fittings yesterday, and have everything assembled. Will be glad to get that stuff on and run it a few months, gotta be thinkin' bout winter....

Some where along the line I think I missed something. What are you doing for a tach install? I wanted one of the LMC tach / fuel gauge kits but not wanting to pay $250 for it I bought a $49 unit that is mounted next to the ash tray. That is not at all ideal, but it gets me a tach which I appreciate when towing.

 

[Craig Nedrow]

Some where along the line I think I missed something. What are you doing for a tach install? I wanted one of the LMC tach / fuel gauge kits but not wanting to pay $250 for it I bought a $49 unit that is mounted next to the ash tray. That is not at all ideal, but it gets me a tach which I appreciate when towing.

I will post pictures here in my K20 build: https://www.gmsquarebody.com/threads/1973-k20-350-to-454-swap.29840/

 

[SirRobyn0]

I will post pictures here in my K20 build: https://www.gmsquarebody.com/threads/1973-k20-350-to-454-swap.29840/

I looked though some of that thread you have a very nice truck, certainly advantages and disadvantages to the beginning of the run vs later on. I've always like the two tone, with the trim like yours. Mine is one color, I call it tan, others like to call it cream. It does have the one solid trim line, mines an 84 c-20. I now have 4 original hub caps and need to get some trim to replace the missing pieces. I had a friend years ago with a 73 w/ 3 on the tree, his was mustard yellow and not a nice truck like yours and mine.